Coating compositions and methods using polyfunctional carbamate salts

Abstract

Described herein are compositions and methods involving latent base catalysts and latent base-catalyzed Michael addition reactions. The described latent base catalysts are substituted carbamate salts. The compositions described herein provide coatings derived from the Michael addition reaction, including primer coatings and direct metal coatings, that have optimal pot life and cure response, and also exhibit optimal adhesion, corrosion resistance, and weather resistance when applied to substrates and cured.

Description

[Background technology]

[0001] Coatings are frequently applied to a variety of substrates, including metal and steel substrates, to protect the substrate from corrosion, impact, and other damage while also providing certain appearance or aesthetic features. Generally, these coatings are economical and relatively easy to apply. These coatings dry quickly and have good corrosion and chemical resistance, making them particularly useful for coating metal components used for long periods of time and / or in corrosive environments.

[0002] Traditionally, many coating systems are crosslinkable two-component compositions that are stored separately and mixed before use. The two components are highly reactive and will begin to crosslink as soon as they are mixed. It is conventional to include a catalyst in such primer coating systems to increase the rate of the crosslinking reaction between the two components.

[0003] The crosslinking reaction can be base-catalyzed or acid-catalyzed. Base-catalyzed systems are sometimes preferred because they allow for rapid or fast curing. However, due to the rapid cure rate, these compositions can only be used for a relatively short period of time after the components are mixed, defined as the pot life of the coating composition. In some base-catalyzed systems, the viscosity increases so rapidly that the coating cures before it can be fully applied to a surface, and therefore these systems are of limited practical use.

[0004] Due to regulatory concerns regarding the use of volatile organic compounds (VOCs) in solvent-borne coatings, high-solids systems with low solvent content are preferred. However, high-solids systems present several challenges with regard to balancing pot life and cure speed. For example, high-solids compositions typically contain small amounts of solvent that can evaporate when the coating is applied, resulting in a pot life that is much shorter than desired. Meanwhile, the increased reaction rate when the coating is applied is also reduced with less solvent in the system, resulting in slower cure. Therefore, the combination of rapid cure and long pot life is difficult to achieve with conventional high-solids coating systems.

[0005] One possible solution to the problem of reduced pot life in base catalysis system is the use of latent catalyst.These catalysts provide a favorable balance between cure speed and pot life.Typically, these catalysts are minimally active until coating is applied, and provide longer pot life without impairing cure speed.For example, the use of substituted carbonate salt as latent catalyst for base catalysis system is described in U.S. Patent No. 8,962,725, which is incorporated herein by reference.

[0006] However, it is not known whether coating compositions using such latent catalyst systems can be used as primer compositions, particularly where excellent weatherability and durability are desired. Furthermore, when some currently known base-catalyzed compositions are applied directly to metal substrates, particularly acidic or acid-treated substrates, a loss in corrosion resistance and / or adhesion is observed.

[0007] Other latent catalysts for base-catalyzed systems are also known, but their synthesis can involve the formation of environmentally harmful by-products that must be eliminated to meet regulatory requirements. For example, the synthesis of carbamate salt latent catalysts is described in U.S. Patent Publication No. 2018 / 0000720, incorporated herein by reference, and volatile amine by-products are formed that must be removed to purify the product for optimal performance. The presence of amines in the system can lead to unwanted side reactions, such as rapid crosslinking, which reduces pot life. Furthermore, discarded amine by-products generated by the purification process can be harmful to the environment.

[0008] Therefore, there is a need for a latent base catalyst that can take advantage of the rapid cure rates and optimal pot life exhibited by latent base catalyst systems that crosslink via the Michael addition reaction and produce coating compositions with optimal corrosion and weather resistance properties. In addition, there is a need for a method of synthesizing latent base catalyst systems that is efficient and does not produce environmentally harmful by-products. Summary of the Invention

[0009] Provided herein are compositions and methods involving a Michael addition reaction catalyzed by a latent base catalyst. The compositions described herein provide coatings derived from the Michael addition reaction that have optimal pot life and optimal cure performance, and also exhibit optimal weatherability.

[0010] In one embodiment, the present specification provides a latent base catalyst of general formula (I): The catalyst is a substituted carbamate salt capable of reacting with at least one crosslinkable component of a crosslinkable resin composition.

[0011] In another embodiment, the present disclosure provides a coating composition comprising at least one crosslinkable polymer containing at least one crosslinkable resin component. The composition comprises a latent base catalyst of general formula (I), wherein the catalyst is a substituted carbamate salt capable of reacting with at least one crosslinkable resin component. In one aspect, the latent catalyst is present in an amount of 0.001 to 1.0 meq, based on the amount of the crosslinkable resin component. The coating composition exhibits optimal pot life and optimal cure response.

[0012] In yet another embodiment, a method for preparing a latent base catalyst is provided, the method comprising providing a hydroxide-functional component and a component capable of reacting with the hydroxide-functional component to produce a latent base catalyst having the general formula (I):

[0013] In one embodiment, the present disclosure provides a cured coating. The coating comprises a polymeric composition including a crosslinkable resin component and a latent catalyst of general formula (I). After application to a substrate, the polymeric coating composition is cured at 150°F (65.5°C) for about 1 to 10 minutes to form a cured coating. As described herein, the cured coating exhibits optimal weatherability.

[0014] The above "Summary" of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies exemplary embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.

[0015] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. Selected Definitions

[0016] Unless otherwise stated, the following terms used herein have the meanings provided below.

[0017] As used herein, the term "organic group" refers to a hydrocarbon group (having optional elements other than carbon and hydrogen, such as oxygen, nitrogen, sulfur, and silicon) classified as an aliphatic group, a cyclic group, or a combination of an aliphatic group and a cyclic group (e.g., alkaryl and aralkyl groups). The term "aliphatic group" refers to a saturated or unsaturated, linear or branched hydrocarbon group. This term is used to encompass, for example, alkyl, alkenyl, and alkynyl groups. The term "alkyl group" refers to a saturated, linear or branched hydrocarbon group, including, for example, methyl, ethyl, isopropyl, tetrabutyl (t-butyl), heptyl, dodecyl, octadecyl, amyl, 2-ethylhexyl, and the like. The term "alkenyl group" refers to an unsaturated, linear or branched hydrocarbon group having one or more carbon-carbon double bonds, such as a vinyl group. The term "alkynyl group" refers to an unsaturated, linear or branched hydrocarbon group having one or more carbon-carbon triple bonds. The term "cyclic group" refers to a closed-ring hydrocarbon group classified as either an alicyclic group or an aromatic group, both of which may contain heteroatoms. The term "alicyclic group" refers to a cyclic hydrocarbon group having properties similar to those of an aliphatic group. The term "Ar" refers to a divalent aryl group (i.e., an arylene group), which refers to a closed aromatic ring or ring system such as phenylene, naphthylene, biphenylene, fluorenylene, and indenyl, as well as a heteroarylene group (i.e., a closed-ring hydrocarbon in which one or more of the atoms in the ring is an element other than carbon, such as nitrogen, oxygen, sulfur, etc.). Suitable heteroaryl groups include furyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, indolyl, isoindolyl, triazolyl, pyrrolyl, tetrazolyl, imidazolyl, pyrazolyl, oxazolyl, thiazolyl, benzofuranyl, benzothiophenyl, carbazolyl, benzoxazolyl, pyrimidinyl, benzimidazolyl, quinoxalinyl, benzothiazolyl, naphthyridinyl, isoxazolyl, isothiazolyl, purinyl, quinazolinyl, pyrazinyl, 1-oxidopyridyl, pyridazinyl, triazinyl, tetrazinyl, oxadiazolyl, thiadiazolyl, and the like.When such groups are divalent, they are typically referred to as "heteroarylene" groups (eg, furylene, pyridylene, etc.).

[0018] Groups that may be the same or different are referred to as being "independently" something. Substitution is anticipated in the organic groups of the compounds of the invention. As a means of simplifying the discussion and listing of certain terms used throughout this application, the terms "group" and "moiety" are used to distinguish between chemical species that may be substituted or substituted and those that may not be substituted or substituted. Thus, when the term "group" is used to describe a chemical substituent, the described chemical includes the unsubstituted group and groups thereof that have, 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, propyl, t-butyl, etc., but also alkyl substituents with 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., while the phrase "alkyl moiety" is limited to including only pure open-chain saturated hydrocarbon alkyl substituents such as methyl, ethyl, propyl, t-butyl, etc.

[0019] The term "component" refers to any compound that contains a particular characteristic or structure. Examples of components include chemical compounds, monomers, oligomers, polymers, and organic groups contained therein.

[0020] The term "double bond" is non-limiting and refers to any type of double bond between any suitable atoms (eg, C, O, N, etc.).

[0021] The term "triple bond" is non-limiting and refers to any type of triple bond between any suitable atoms.

[0022] As used herein, "Michael addition" refers to the nucleophilic addition of a carbanion or other nucleophile to an electron-deficient ethylenically unsaturated compound, such as, for example, an α,β-unsaturated carbonyl compound. The abbreviation "MA" is used interchangeably with the term "Michael addition" herein.

[0023] The Michael addition reaction follows the general reaction scheme shown herein. [ka]

[0024] In the reaction schematic shown above, B is a latent base catalyst that reacts with a Michael addition (MA) donor by deprotonation to form a carbanion for subsequent addition reaction with an MA acceptor.

[0025] As used herein, the term "resin composition" refers to the resin-containing portion of a composition. A resin composition may contain one or more resin or polymer components. Suitable examples include, but are not limited to, MA donors, MA acceptors, non-functional resins, and resins with functionality other than the required Michael addition. This term is used interchangeably herein with "polymer" or "polymer composition." As used herein, a resin or polymer composition may contain one or more resin components.

[0026] By "Michael addition acceptor" or "MA acceptor" is meant a molecule that has at least one MA acceptor functional group.

[0027] "Michael addition donor" or "MA donor" means a molecule that has at least one MA donor functional group.

[0028] "MA acceptor / donor" means a molecule having at least one Michael addition (MA) acceptor functional group and at least one Michael addition (MA) donor functional group.

[0029] The term "crosslinker" refers to a molecule that can form a covalent bond between polymers or between two different regions of the same polymer. A particular component is said to be "crosslinkable" if it can react with another component through a crosslinking reaction, either through a self-crosslinking reaction or through the reaction of two or more polymers or between two different regions of the same polymer.

[0030] The term "self-crosslinking," when used in the context of a self-crosslinking polymer, refers to the ability of the polymer to enter into a crosslinking reaction with itself and / or another molecule of the polymer to form a covalent bond between them in the absence of an external crosslinking agent. Typically, this crosslinking reaction occurs through the reaction of complementary reactive functional groups present on the self-crosslinking polymer itself, or two separate molecules of the self-crosslinking polymer.

[0031] The term "dispersion" in the context of dispersible polymers refers to a mixture of dispersible polymer and carrier. The term "dispersion" is intended to include the term "solution."

[0032] The term "on," when used in the context of a coating applied to a surface or substrate, includes both coatings applied directly or indirectly to the surface or substrate. Thus, for example, a coating applied to a primer layer overlying a substrate constitutes a coating applied to the substrate.

[0033] As used herein, the term "dry to handle" refers to the stage in the substrate coating process where the applied coating is sufficiently cured to move on to the next stage in the manufacturing process.

[0034] Unless otherwise indicated, the term "polymer" includes both homopolymers and copolymers (ie, polymers of two or more different monomers).

[0035] The terms "comprises" and variations thereof do not have a limiting meaning where these terms appear in the description and claims.

[0036] The terms "preferred" and "preferably" refer to embodiments of the invention that may offer certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.

[0037] As used herein, "a," "an," "the," "at least one," and "one or more" are used interchangeably. Thus, for example, a coating composition that includes "an" additive can be interpreted to mean that the coating composition includes "one or more" additives.

[0038] Also herein, the recitation of numerical ranges by endpoints includes all numbers subsiding within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Further, the disclosure of a range includes the disclosure of all subranges subsumed within that broader range (e.g., 1 to 5 discloses 1 to 4, 1.5 to 4.5, 1 to 2, etc.). DETAILED DESCRIPTION OF THE INVENTION

[0039] Provided herein are latent base catalysts, methods of making such catalysts, and coating compositions for various substrates, including metal and steel substrates. Specifically, provided herein are coating compositions for untreated or pretreated substrates, including, for example, steel substrates, where these coatings are derived from components that cure via a Michael addition reaction catalyzed by the latent bases described herein.

[0040] The present disclosure provides a latent base catalyst. In one embodiment, the latent base catalyst is a substituted carbamate salt having the structure of general formula (I): [ka] During the ceremony, each X + are independently non-acidic cations, each R1 is independently H, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; each R2 and R3 is independently a C1-C10 alkyl, aryl, aralkyl, or a C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; n is greater than 1. The latent base catalyst having the structure in general formula (I) is capable of reacting with at least one crosslinkable component of a crosslinkable polymer or resin composition.

[0041] Without being limited by theory, the latent base catalyst of general formula (I) is believed to function by releasing carbon dioxide when the carbamate salt decomposes as a wet film upon application to a substrate. In a closed pot, this reaction occurs slowly, extending pot life. When a coating is applied and the surface area increases, the base is quickly regenerated, allowing carbon dioxide to escape from the surface, allowing the coating to cure (i.e., dry and harden) more quickly. Thus, the use of the latent base catalyst of general formula (I) allows for optimal pot life, open time, and cure performance for the crosslinkable coating compositions described herein.

[0042] In the latent base catalyst having the structure of general formula (I), X + is a non-acidic cation. When n in formula (I) is greater than 1, each X in one unit of the latent base catalyst + is the X in another unit of the same latent base catalyst molecule. + may be the same as or different from

[0043] Suitable examples include, but are not limited to, alkali metal ions, alkaline earth metal ions, ammonium ions, phosphonium ions, etc. In a preferred embodiment, X + is a lithium ion, a sodium ion, a potassium ion, or the like. More preferably, X + is a quaternary ammonium ion NR'4 or a phosphonium ion PR'4, where R is H, unsubstituted C1-C10 alkyl, aryl, aralkyl, substituted C1-C10 alkyl, aryl, aralkyl, and mixtures or combinations thereof. In a preferred embodiment, R is an unsubstituted alkyl group having 1 to 4 carbon atoms. If the R group is substituted, the substituents are selected so as not to substantially interfere with the crosslinking reaction. In one embodiment, acidic substituents, such as, for example, carboxylic acid substituents, are present in negligible amounts or are absent altogether to avoid interfering with the action of base catalysis.

[0044] In the latent base catalyst of general formula (I), R1 is hydrogen, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof. In a preferred embodiment, R1 is hydrogen.

[0045] In the latent base catalyst of general formula (I), R2 and R3 are each independently a C1-C10 alkyl, aryl, aralkyl, or a C1-C10 substituted alkyl, aryl, aralkyl, or mixtures or combinations thereof. In a preferred embodiment, R2 and R3 are each independently an unsubstituted alkyl group having 1 to 4 carbon atoms, more preferably 4 carbon atoms.

[0046] The latent catalysts described herein are substituted carbamate salts synthesized by the reaction of a hydroxide-functional component with a component capable of reacting with the hydroxide-functional component. In one aspect, the hydroxide-functional component is a hydroxide base and the component capable of reacting with the hydroxide base is a polyfunctional isocyanate.

[0047] Suitable hydroxide bases for use in the methods described herein include, but are not limited to, tetrahexylammonium hydroxide, tetradecyl-(i.e., C14)-trihexylammonium-hydroxide and tetradecylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, or trihexylmethylammonium hydroxide or trioctylmethylammonium hydroxide, and mixtures or combinations thereof.

[0048] To prepare the latent base catalyst described herein, the hydroxide-functional component is reacted with a polyfunctional isocyanate. Suitable polyfunctional isocyanate compounds include, but are not limited to, 2,4-toluene diisocyanate, hexamethylene diisocyanate (HDI), polymethylene-polyphenyl diisocyanate, methylene diphenyl diisocyanate, cyclic trimers, cocyclic trimers, homopolymers, copolymers, or mixtures thereof. In a preferred embodiment, the polyfunctional isocyanate is a trimer. Examples of suitable trimers include, but are not limited to, trimerization products prepared from an average of three diisocyanate molecules, or trimers prepared from an average of three moles of a diisocyanate (e.g., HDI) reacted with one mole of another compound, such as a triol (e.g., trimethylolpropane). In a preferred embodiment, the polyfunctional isocyanate is an HDI trimer.

[0049] The reaction of the hydroxide-functional component with the polyfunctional isocyanate can be carried out in the presence of an alcohol, such as methanol. Without being limited by theory, it is believed that when the reaction is carried out in the presence of an alcohol, any isocyanate that does not react with the hydroxide reacts with the excess methanol in the solution. However, reaction in the presence of an alcohol is not necessary; the alcohol can be added at the end of the synthesis, i.e., after the hydroxide-functional component has reacted with the polyfunctional isocyanate.

[0050] The latent catalysts described herein are carbamate salts prepared by reacting a hydroxide base, preferably tetrabutylammonium hydroxide, with a polyfunctional isocyanate, preferably the trimer of HDI. In one embodiment, the latent catalysts described herein contain multiple carbamate moieties, preferably two or more carbamate moieties. In one embodiment, the ratio of hydroxide groups to isocyanate groups in the latent catalyst is 0.60:1.0 to 0.99:1.0, preferably 0.7:1.0 to 0.99:1.0. More preferably, the latent catalyst has a hydroxide group to isocyanate group ratio of 0.9:1.0, i.e., the catalyst has an index of 0.9 relative to the amount of isocyanate groups present. Any excess isocyanate in the system that does not react with the hydroxide will react with excess methanol, water, or other solvent present in the solution.

[0051] In a preferred embodiment, the described latent base catalyst is prepared by the reaction of tetrabutyl ammonium hydroxide (TBAH) with hexamethylene diisocyanate. This latent base catalyst has the structure shown in formula (II). [ka]

[0052] In one embodiment, the latent catalyst described herein is a carbamate salt made by the reaction of a hydroxide base with a polyfunctional isocyanate, and the reaction is overindexed on the polyfunctional isocyanate. That is, the reaction includes an excess of isocyanate to ensure complete conversion of the hydroxide to carbamate. Any excess isocyanate remaining after the reaction is consumed with excess methanol, water, or other solvent present in the solution.

[0053] In another embodiment, the latent catalyst described herein is a carbamate salt made by the reaction of a hydroxide base with a polyfunctional isocyanate, and the reaction is over-indexed on the hydroxide. That is, the reaction includes an excess of hydroxide to ensure complete conversion to carbamate. Any excess hydroxide remaining after the reaction is titrated with the addition of acid to remove excess base from the system. In one embodiment, the excess hydroxide is present in an amount up to about 10%, preferably less than 10%, and more preferably the minimum excess amount practical to consume all the isocyanate.

[0054] The latent catalysts described herein are used to prepare coating compositions, including two-component coating compositions. In one embodiment, the coating compositions are made by reacting the latent catalyst with a crosslinkable polymer composition through a Michael addition reaction. The polymer composition includes at least one crosslinkable resin component, but may also include non-functional resins, resins with functionality other than that required for the Michael addition, etc.

[0055] The Michael addition reaction involves the nucleophilic addition of a carbanion or other nucleophile to an electron-deficient ethylenic compound. The nucleophile, referred to as the Michael addition (MA) donor, can be any organic compound containing at least one active hydrogen and at least one electron-withdrawing group, such as -CN, -COOR, or -COR. The Michael addition (MA) acceptor is typically an ethylenically unsaturated compound with a double bond that can be activated by a carbonyl group in the alpha position.

[0056] Suitable examples of MA donors include, but are not limited to, dialkyl malonates (e.g., dimethyl malonate, diethyl malonate, etc.), cyanoacetates (e.g., methyl cyanoacetate, ethyl cyanoacetate, etc.), chloroacetates, acetoacetates, propionyl acetate, malononitrile, acetonitrile, acetylacetone, dipropionylmethane, etc., and mixtures or combinations thereof. Preferred examples of MA donors include, but are not limited to, malonate- or acetoacetate-group-containing oligomeric and polymeric compounds, such as polyesters, polyurethanes, polyacrylates, epoxy resins, polyamides, and polyvinyl resins containing malonate- or acetoacetate-functional groups in the backbone, pendant, or both.

[0057] Suitable examples of MA acceptors include, but are not limited to, esters of (meth)acrylic acid, i.e., (meth)acrylate-functional compounds derived from the reaction of a hydroxyl-functional compound (i) with (meth)acrylic acid or its ester derivative (ii), where the hydroxyl-functional compound can be mono-, di-, or polyfunctional and has a backbone containing an aliphatic, alicyclic, or aromatic chain, such as (poly)epoxy, (poly)ether, (poly)ester, e.g., (poly)caprolactone, (poly)alkyd, (poly)urethane, (poly)amine, (poly)amide, (poly)carbonate, (poly)olefin, (poly)siloxane, (poly)acrylate, halogen (e.g., fluorine), melamine derivative, copolymers of any of these, and the like, as well as mixtures and combinations thereof.

[0058] The crosslinkable polymer composition can include one or more MA donor components and one or more MA acceptor components. In a preferred embodiment, the crosslinkable polymer composition includes at least one malonate-functional MA donor component and at least one acrylate-functional MA acceptor component. Exemplary crosslinkable compositions are as described in applicants' co-pending patent application PCT / US2019 / 031069, filed May 7, 2019, which is incorporated herein by reference.

[0059] Without being limited by theory, it is believed that the MA acceptor and MA donor components react via a Michael addition reaction, thereby helping to improve cure speed, crosslink density, and hardness development for the coating compositions described herein. Improved cure and increased crosslink density will lead to improved performance characteristics.

[0060] The MA donor and MA acceptor are present in a crosslinkable polymer composition that reacts with a latent base catalyst described herein to produce a coating composition with optimal cure and weatherability performance. In one aspect, the crosslinkable polymer composition is one part (e.g., part A) of a two-component coating composition, having a latent base catalyst described herein as the other part (e.g., part B).

[0061] The coating compositions described herein are made by reacting a latent base catalyst (Part B) with a crosslinkable polymer composition (Part A), where the ratio of A:B can vary depending on the desired reaction conditions and end use. In one embodiment, the amount of latent base catalyst used herein can vary depending on the properties of the coating composition. Preferably, the composition contains about 0.001 to 1 meq, more preferably 0.02 to 0.07 meq, based on the amount of resin solids in the composition.

[0062] In one embodiment, a non-latent base catalyst can be used alone or in combination with the latent base catalysts described herein to promote the Michael addition reaction. Examples of suitable non-latent catalysts include, but are not limited to, tetrabutylammonium hydroxide, ammonium hydroxide, DBU (8-diazabicyclo[5.4.0]undec-7-ene), DBN (1,5-diazabicyclo[4.3.0]non-5-ene), and TMG (1,1,3,3-tetramethylguanidine).

[0063] Suitable additional examples of non-latent catalysts include, but are not limited to, K + , Na + , Li+ or basic anions X from compounds containing acidic XH groups. - and the salts of weakly acidic cations, such as protonated species of strong organic bases, such as DBU, DBN, etc., or TMG, paired with the anion X - is an MA donor that can react with an MA acceptor (e.g., acrylate), and an anion X - has a pKa of the corresponding acid XH that is more than two units lower than the pKa of most donor components (e.g., acetoacetate-functional resins). Suitable examples of such salts include, but are not limited to, salts formed from the reaction of KOH and benzotriazole, TBAH and benzotriazole, or KOH and 1,2,4-triazole, at levels of 0.001 to 1 meq / gram of solid resin. Mixtures or combinations of the above may be used. A preferred non-latent catalyst is a solution of potassium benzotriazolide formed from the reaction of equal molar ratios of KOH and benzotriazole in ethanol.

[0064] Optionally, one or more additional components may be included to extend the open time and pot life, such as, for example, one or more acidic X'-H groups, where X' is N, P, O, S, or C, and where X ’ The anion is an MA donor capable of reacting with an MA acceptor, and the pKa of the X'-H group is lower, preferably more than two units lower, than the pKa of most MA donors (e.g., acetoacetate-functional resins). Suitable examples include, but are not limited to, ethyl acetoacetate, benzotriazole, succinimide, acetylacetone, or 1,2,4-triazole, and mixtures or combinations thereof. In a preferred embodiment, the component is benzotriazole present in an amount of about 0.5-5%, more preferably about 0.5-1.5%, based on the total weight of resin solids.

[0065] In one embodiment, the coating composition described herein includes an acid scavenger or pH buffering component. Suitable examples include, but are not limited to, metal oxides (e.g., zinc oxide, nanoparticulate zinc oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, lanthanum oxide, ytterbium oxide, zirconium oxide, etc.), mixed metal oxides (e.g., MgO-TiO, etc.), zeolites (e.g., cesium-exchanged zeolites, X, Y-Cs-occluded zeolites, etc.), modified mesoporous materials (e.g., MgO-coated mesoporous silica (SBA-15), amino-functionalized mesoporous silica (MCM-41), mesoporous silicon oxynitride, etc.), metal hydroxides (e.g., calcium hydroxide, Na / NaOH / AlO, Na / MgO, etc.), metal nitrides, metal oxynitrides (e.g., silicon oxynitrides, aluminophosphate oxynitrides, zirconium oxynitrides, etc.), and the like. phosphates, calcined NaNO3, etc.), metal carbonates (e.g., calcium carbonate, sodium carbonate, magnesium carbonate, etc.), metal silicates (e.g., calcium silicate, calcium borosilicate, magnesium silicate, Mg-Al hydrotalcite, chrysotile, etc.), metal carboxylates (e.g., titanium acetylacetate, etc.), organometallic compounds (e.g., organozirconates, weak base titanates, tetraalkyl titanates, etc.), amines (e.g., guanidine, aziridine, amidine, triethanolamine, DMP30, etc.), imides (e.g., carbodiimides, etc.), diaza-bicyclo compounds (e.g., DABCO, etc.), and mixtures or combinations thereof.

[0066] Thus, the coating compositions described herein can be applied over an acidic substrate, such as a metal substrate, having a pretreatment applied thereto. Suitable examples of pretreatments include, but are not limited to, iron phosphate, zinc phosphate, silane, zirconium, and the like. Many other pretreatments are known in the metal pretreatment industry. In a preferred embodiment, the metal substrate has an iron phosphate treatment applied thereto.

[0067] The coating compositions described herein may also contain other optional ingredients that do not adversely affect the coating composition or the cured coating composition obtained therefrom. Such optional ingredients are typically included in the coating composition to enhance the coating's aesthetics, to facilitate the manufacture, processing, handling, and application of the composition, and to further improve certain functional properties of the coating composition or the cured coating composition obtained therefrom. For example, the compositions described herein may optionally include adhesion promoters, fillers, catalysts, lubricants, pigments, surfactants, dyes, colorants, toners, coalescing agents, extenders, corrosion inhibitors, flow control agents, thixotropic agents, dispersants, antioxidants, adhesion promoters, light stabilizers, and mixtures thereof, as needed to provide desirable film properties. Each optional ingredient 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 composition obtained therefrom.

[0068] In one embodiment, the compositions described herein may include, in addition to the MA donors and MA acceptors described herein, resin components that do not undergo a Michael addition reaction. These additional resin components may have no reactive functional groups or may have reactive functional groups that undergo reactions other than a Michael addition reaction.

[0069] In one embodiment, the coating compositions described herein may contain a solvent. Suitable solvents may be aqueous, organic, or a mixture thereof. Suitable examples of organic solvents include, but are not limited to, aliphatic solvents, aromatic and / or alkylated aromatic solvents (e.g., toluene, xylene, etc.), alcohols (e.g., isopropanol), esters (e.g., methoxypropanol acetate, butyl acetate, isobutyl acetate, etc.), ketones (e.g., methyl ethyl ketone, methyl amyl ketone, etc.), glycol ethers, glycyl ether esters, and mixtures or combinations thereof. In one aspect, the coating compositions described herein have a low volatile organic compound (VOC) content, preferably less than 400 g / L, more preferably less than 300 g / L, and most preferably less than 250 g / L.

[0070] The compositions described herein also exhibit comparable shelf life and an optimal balance of pot life and dry time relative to conventional polyurethane coatings and knowledge of such coatings in the art. In one aspect, the compositions described herein have an optimal shelf life, exhibiting no loss of cure response or any viscosity increase after storage at a temperature of about 120°F (48.8°C) for at least one week. In another aspect, the coating compositions described herein also exhibit an optimal pot life, with the compositions taking preferably more than 60 minutes, more preferably more than 120 minutes, for their viscosity to double after mixing.

[0071] In one embodiment, the coating compositions described herein exhibit improved cure response relative to systems that do not contain a latent base catalyst. In one aspect, the coating compositions described herein have optimal cure response, as assessed by pencil hardness testing after the coating is applied to a substrate and cured. Optimal cure response means that the coating composition dries to a handleable state in about 1 to 30 minutes, preferably about 1 to 10 minutes, after drying at ambient temperature, including room temperature, for example, 75 to 77°F (about 24 to 25°C). Optimal cure can also be affected by baking at elevated temperatures, including about 100°F (37.7°C), 200°F (93.3°C), 300°F (148.9°C), and even higher. In a preferred aspect, optimal cure response is observed when the coating composition is baked at a temperature of about 150°F (65.5°C).

[0072] The coating compositions described herein may be used as primers or may be part of a primer formulation. When used as a primer or in a primer formulation, the compositions described herein may be applied over untreated substrates, pre-treated substrates, substrates having a temporary coating applied thereon, and the like.

[0073] The coating compositions described herein, when used as primers, exhibit optimal corrosion resistance, meaning that cured coatings derived from the compositions described herein exhibit creep from the scribe of less than 3 mm, preferably less than 2 mm, after salt spray exposure.

[0074] The coating compositions described herein can be used as topcoats. In one embodiment, a first coating (e.g., a primer, etc.) is applied over an untreated substrate, a pretreated substrate, a substrate having a temporary coating applied thereon, etc. Then, if necessary, a second coating (e.g., a topcoat, etc.) is applied over the primer. In one embodiment, the second coating is applied only after the first coating has completely dried or cured. In an alternative embodiment, the second coating is applied over the first coating before the first coating has completely dried or cured.

[0075] The compositions described herein can be used as both a primer and a topcoat as part of a coating system applied to a substrate. In one embodiment, a first coating, i.e., a coating composition described herein, is applied as a primer over an untreated substrate, a pretreated substrate, a substrate having a temporary coating applied thereon, or the like. Then, if necessary, a second coating, i.e., a coating composition described herein, is applied as a topcoat over the primer. In one embodiment, the second coating is applied only after the first coating has completely dried or cured. In an alternative embodiment, the second coating is applied over the first coating before the first coating has completely dried or cured.

[0076] The coating compositions described herein are intended for outdoor use and / or are intended to be weatherable coatings, such as topcoats or direct-to-metal (monocoat) applications, i.e., cured coatings formed from the compositions described herein exhibit optimum weatherability. Optimum weatherability means a coating that exhibits at least 60%, preferably at least 70%, 20° gloss retention, and at least 70%, preferably at least 80%, 60° gloss retention after 2000 hours of accelerated weathering in a xenon arc weathering chamber. Alternatively, the measured color shift (ΔE 00) is less than 1.0, preferably less than 0.5 units, the coating has optimum weather resistance.

[0077] In one embodiment, the coating compositions described herein can be used as primers, and an optional topcoat can be applied over the described primers. In one aspect, the topcoat composition is also obtained by a Michael addition reaction. The Michael addition-derived topcoat can be the same as or different from the Michael addition-derived primer compositions described herein. In another aspect, the topcoat composition is not derived from a Michael addition reaction, but can be components known in the art as suitable topcoat materials, such as, for example, polyurethane topcoats.

[0078] Previously, Michael addition-derived coating compositions have demonstrated improved cure response over traditional primers made with polyurethanes, epoxies, non-isocyanate systems, and the like. However, the use of such Michael addition-derived coatings has been limited due to poor adhesion to various substrates and, particularly, due to a lack of corrosion resistance when applied as a primer or as a direct-to-metal (DTM) coating on metal substrates, particularly pretreated steel substrates. Surprisingly, the Michael addition-derived coating compositions described herein can be used as primers or as DTM coatings with optimal corrosion resistance.

[0079] The coating composition of the present invention can be applied to a substrate either before or after the substrate is formed into an article. In one embodiment, the coating composition described herein can be applied to a variety of substrates. Suitable examples include, but are not limited to, natural and artificial buildings and building materials, cargo containers, flooring materials, walls, furniture, other building materials, automobiles, automobile parts, aircraft parts, trucks, railroad cars and engines, bridges, water towers, cell phone towers, wind power towers, radio towers, lighting fixtures, statues, sign supports, fences, guardrails, tunnels, pipes, marine parts, machine parts, laminates, equipment parts, electrical appliances, and packaging materials. Exemplary substrate materials include, but are not limited to, wood, plastics, thermoset resins, metals, metal alloys, intermetallic compositions, metal-containing composites, and combinations thereof. Exemplary metal substrates include, but are not limited to, aluminum, steel, weathering steel, and stainless steel. In a preferred embodiment, the substrate is steel, preferably steel with a pretreatment applied thereto.

[0080] The coating compositions described herein can be applied by any method known in the art. Standard methods of application include, but are not limited to, brushing, spraying, spin coating, roll coating, curtain coating, dipping, gravure coating, bell coating, etc. In the case of two-component thermosetting substrates, the coating can be applied via an in-mold process. When the coating composition is applied by spraying, both conventional air or air-assisted spray equipment, or airless spray equipment can be used. Both electrostatic and non-electrostatic equipment can be used.

[0081] The coating thickness of the particular layer and of the overall coating system will vary depending on the coating material used, the substrate, the coating application method, and the end use for the coated article. When used as a primer applied over an untreated or pretreated metal substrate, the thickness of the applied coating film is preferably about 0.05 to 20 mils (1.27 to 500 microns), more preferably 0.4 to 40 mils (10 to 100 microns), and even more preferably 1.0 to 2.5 mils (25 to 70 microns). [Example]

[0082] The present invention is illustrated by the following examples. It should be understood that the specific examples, materials, amounts, and procedures should be interpreted broadly in accordance with the scope and spirit of the invention as described herein. Unless otherwise indicated, all parts and percentages are by weight, and all molecular weights are weight average molecular weights. Unless otherwise specified, all chemicals used are commercially available, for example, from Sigma-Aldrich (St. Louis, Missouri).

[0083] Unless otherwise indicated, the following test methods were utilized in the following examples. Corrosion resistance (salt spray)

[0084] The corrosion resistance of cured coatings prepared using the compositions and methods described herein is tested using the salt fog method as described in ASTM B117 (Standard Practice for Operating Salt Fog Apparatus). Results are expressed in terms of blistering (ASTM D714), rusting (ASTM D610), and creep from the scribe (ASTM D1654-08). Creep from the scribe is expressed on a scale of 0 to 10, with 0 indicating extensive corrosion at the scribe and 10 indicating the coating is unchanged from exposure to the corrosive environment. Rust ratings for coatings exposed to salt fog in a humid environment are also expressed on a scale of 0 to 10, with 0 indicating complete surface rusting and 10 indicating no surface rusting. Blister ratings are expressed on a scale of 0 to 10, with 0 indicating excessive blistering and 10 indicating no blistering. Corrosion resistance (creep)

[0085] The corrosion resistance of cured coatings formed from the compositions described herein is also tested by measuring creep after exposure to a corrosive environment, as described in ASTM D1654-08 (Standard Test Method for Evaluation of Painted or Coated Specimens Subject to Corrosive Environments). The coating is applied to a panel and then cured. The panel is then scribed to metal and exposed to salt spray for a given period of time. The paint loss from the scribe is measured, and the results are expressed as the amount of creep from the scribe (mm). For commercially viable coatings, creep from the scribe of 2 mm or less is desired. Pot Life Evaluation

[0086] The pot life of the coating compositions described herein is determined by measuring the viscosity of the composition over a given period of time under a given set of conditions, such as at room temperature or after storage in a hot box. In the examples herein, viscosity is determined as follows: A Zahn cup is immersed in a sample of the coating composition until it is completely filled with the sample. The cup is then lifted, and the flow time for the sample is measured in seconds and reported along with the specific Zahn cup number. Pot life is reported as the time it takes for the viscosity of the coating composition sample to double. Effective hardening (hardness)

[0087] The effectiveness of the curing of a coating can be evaluated by measuring the hardness of the cured coating using the pencil hardness method, as described in ASTM D3363 (Standard Test Method for Film Hardness by Pencil Test). Pencils of various hardnesses, ranging from 6B (softest) to 6H (hardest), are applied to the surface of the cured coating. The results are expressed as the hardest pencil that does not mar or scratch the surface of the cured coating applied to the test panel. Thus, for example, if a coating is not damaged by a 2H pencil but is damaged when a 3H pencil is used, the pencil hardness of the coating is 2H. Curing speed (Konig)

[0088] The hardness of the cured coating can also be evaluated by the Konig pendulum hardness test, as described in ASTM D4366 (Standard Test Methods for Hardness of Organic Coatings by Pendulum Damping Test). A pendulum is oscillated across the cured coating, and the hardness of the cured coating is expressed as the damping time (in seconds) until the deflection of the pendulum slows to a specified value. catalyst stability

[0089] Hardness measurements can also be used to evaluate the stability of the latent catalysts described herein: the catalysts are stored in a hot box for a given period of time, after which cured coatings prepared with the catalyst and baked at a given temperature for a given period of time are then tested for hardness using both the pencil hardness method and the Konig pendulum hardness method. Example 1: Synthesis of catalyst and coating composition

[0090] To 3.68 g of a 10% solution of tetrabutylammonium hydroxide (TBAH) in methanol, 6.59 g of OXSOL 100 was added and mixed. Then, 1.32 g of hexamethylene diisocyanate trimer (HDI trimer) solution was added dropwise with thorough mixing. A hydroxide to isocyanate functional group ratio of 0.9:1.0 was maintained, resulting in excess isocyanate. Any isocyanate that did not react with the hydroxide is believed to have reacted with the excess methanol in solution.

[0091] The 0.9 index catalyst (Part B) prepared above was combined with a batch of finished paint (Part A) containing a malonate-functional Michael addition donor component and an acrylate-functional Michael addition acceptor component. Parts A and B were mixed in a ratio of 10:1 (A:B) to form a coating composition of the present invention. As a control, a composition was prepared using the same Part A above combined with a 6% solution (i.e., a diluted solution) of a latent catalyst (commercially available as ACURE 500 from Allnex) as Part B. Example 2: Cure Performance

[0092] The control and inventive coating compositions prepared in Example 1 were applied to pre-treated metal test panels at a dry film thickness of approximately 2 mils (50.8 μm). The cure performance of the coatings was then evaluated by curing and baking the coatings at given temperatures for given periods of time as shown in Table 1 below, and then testing the cured coatings for pencil hardness and Konig pendulum hardness. The results are shown in Table 1. [Table 1] Example 3: Catalyst Stability

[0093] To evaluate the stability of the latent base catalysts described herein, the 0.9 index catalyst prepared in Example 1 was placed in a hot box at 120°F (48.8°C) for one week. The cure performance of the coating was then evaluated as in Example 2. A control sample was used as in Example 2 for comparison. The results for cure performance are shown in Table 2. [Table 2] Example 4: Pot Life

[0094] To determine the effect of the latent catalyst described herein on the pot life of a coating composition, the 0.9 index catalyst (Part B) from Example 1 was mixed with a batch of the finished paint (Part A) from Example 1 in a 10:1 (A:B) ratio. The initial viscosity was measured using a #3 Signature Zahn cup and again after 180 minutes. In addition, the coating composition was placed in a hot box at 120°F (48.8°C) for one week, and the initial viscosity was measured, followed by a viscosity measurement after 180 minutes. The results are shown in Table 3A. [Table 3]

[0095] The effect of water on pot life was also evaluated for the coating compositions described herein. A sample of the finished paint from Example 1 (Part A) was mixed 10:1 by weight with the 0.9 Index catalyst from Example 1 (Part B) to make a coating composition. Half was used as a control, and the other half was combined with a 1:1 solution of 2 wt.% water and acetone. Initial viscosity was measured using a #3 Signature Zahn cup and expressed as time to efflux (minutes), with additional viscosity measurements taken at specified time points thereafter. The results are shown in Table 3B. [Table 4] Example 5: Performance Characteristics (Cure Response and Corrosion Resistance)

[0096] To determine the performance of the coatings described herein, primer compositions A, B, C, and D were prepared containing a resin component crosslinkable by Michael addition. Compositions A, B, and C were prepared with a catalyst index of 0.9 at the levels shown in Table 4. Composition D was a control prepared with a commercially available latent base catalyst (ACURE 500, Allnex) at the levels shown in Table 4.

[0097] Each composition was spray applied to a metal test panel at a dry film thickness of approximately 2.0 mils (50 μm). Each panel was then cured at 150°F (65.5°C) for 10 minutes. The cure response for each sample (3-4 replicates for each composition) was evaluated using the Konig pendulum hardness test.

[0098] To determine the corrosion resistance of the coating compositions, Samples A, B, C, and D were spray-applied to phosphate-treated cold-rolled steel test panels (ACT B1000 P99X) at a dry film thickness of approximately 1.5 to 2.0 mils (38 to 50 μm) and force-cured for 30 minutes at 150°F (65.5°C). The panels were then placed in a salt spray cabinet for 500 hours as described in ASTM B117. Corrosion resistance was evaluated for each sample by assessing blistering, rust, and creep from scribes. The results are shown in Table 4. [Table 5]

[0099] A comparison of the cure performance and salt spray results for the composition of the present invention (Sample B) and the control composition (Sample D) shows similar performance.

[0100] The complete disclosures of all patents, patent applications, and publications cited herein, as well as electronically available materials, are incorporated by reference. The foregoing "Description of Embodiments" and examples are given for clarity of understanding only. No unnecessary limitations should be understood therefrom. The invention is not limited to the exact details shown and described; variations obvious to those skilled in the art will be included within the invention defined by the claims. The invention illustratively disclosed herein may, in some embodiments, be practiced in the absence of any element not specifically disclosed herein. [1] A latent base catalyst comprising: A substituted carbamate salt having a structure of general formula (I): [ka] During the ceremony, each X + are independently non-acidic cations, each R1 is independently H, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; each R2 and R3 is independently a C1-C10 alkyl, aryl, aralkyl, or a C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; n is greater than 1, including substituted carbamate salts; The latent base catalyst is capable of reacting with at least one crosslinkable component of a crosslinkable resin composition. [2] 1. A coating composition comprising: a crosslinkable polymer comprising at least one crosslinkable resin component; A latent catalyst having a structure of general formula (I): [ka] During the ceremony, each X +are independently non-acidic cations, each R1 is independently H, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; each R2 and R3 is independently a C1-C10 alkyl, aryl, aralkyl, or a C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; a latent catalyst, wherein n is greater than 1; and a coating composition comprising: [3] 1. A method for preparing a latent catalyst, comprising: providing a hydroxide-functional component; providing a multifunctional component capable of reacting with said hydroxide-functional component; reacting the hydroxide-functional component with the component capable of reacting with the hydroxide-functional component to produce a latent catalyst having the structure of general formula (I): [ka] During the ceremony, each X + are independently non-acidic cations, each R1 is independently H, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; each R2 and R3 is independently a C1-C10 alkyl, aryl, aralkyl, or a C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; method, where n is greater than 1. [4] 1. A cured coating comprising: a crosslinkable resin component; a latent catalyst having a structure of general formula (I): [ka] During the ceremony, each X + are independently non-acidic cations, each R1 is independently H, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; each R2 and R3 is independently a C1-C10 alkyl, aryl, aralkyl, or a C1-C10 substituted alkyl, aryl, aralkyl, or a mixture or combination thereof; n is greater than 1, including polymeric coating compositions; After application to the substrate, the polymeric coating composition is cured at 150°F (65.5°C) for about 1 to 10 minutes to form the cured coating; The cured coating exhibits optimal curing performance. [5] X + is selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion, a phosphonium ion, or a combination thereof. [6] X + is a quaternary ammonium cation or a phosphonium ion. [7] X + is a quaternary ammonium cation having the general formula NR'4, [6] The composition or method according to any one of [1] to [6], wherein R' is H, unsubstituted C1 to C10 alkyl, substituted C1 to C10 alkyl, aryl, aralkyl, or a mixture or combination thereof. [8] X + is a quaternary ammonium cation having the general formula NR'4, where R' is a C1-C4 unsubstituted alkyl. [9] The composition or method according to any one of [1] to [8], wherein the latent catalyst is present in an amount of about 0.1 to 1.0 meq.

[10] The composition or method according to any one of [1] to [9], wherein the latent catalyst is present in an amount of about 0.01 to 0.5 meq.

[11] The method of [3], wherein the hydroxide-functional compound is selected from a C1-C10 alkyl ammonium hydroxide, an aryl ammonium hydroxide, an aralkyl ammonium hydroxide, or a combination thereof.

[12] The method according to [3], wherein the hydroxyl-functional compound is a C1-C10 alkylammonium hydroxide.

[13] The method according to

[12] , wherein the C1 to C10 alkylammonium hydroxide is tetrabutylammonium hydroxide.

[14] The method of [3], wherein the component capable of reacting with a hydroxyl-functional component is a multifunctional isocyanate.

[15]

[15] The method according to

[15] , wherein the polyfunctional isocyanate is selected from 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-methylene diphenyl diisocyanate, hexamethylene diisocyanate, polymethylene-polyphenyl isocyanate, homopolymers thereof, cyclic trimers thereof, cocyclic trimers thereof, and mixtures thereof.

[16]

[15] The method according to

[15] , wherein the polyfunctional isocyanate is a hexamethylene diisocyanate trimer, a hexamethylene diisocyanate homopolymer, or a combination thereof.

[17]

[15] The method of

[15] , wherein any polyfunctional isocyanate that does not react with the hydroxyl-functional compound reacts with excess solvent in the solution.

[18] optionally comprising a pot life or open time extending component comprising one or more acidic X'-H group containing compounds; wherein X' is N, P, O, S, or C, and X'H has a pKa at least 1 unit less than that of a Michael addition donor component present in the composition. [1] -

[17] .

[19] [4] The coating of [4], wherein the substrate is selected from pretreated metal, wood, plastic, polymeric material, ceramic material, glass, or a combination thereof.

Claims

1. General formula (I): 【Chemistry 1】 [In the formula, Each X ＋ are independently non-acidic cations, Each R １ are independently selected from H, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl; Each R ２ are independently selected from C1-C10 alkyl, aryl, aralkyl, or a group in which one hydrogen has been removed from a C1-C10 substituted alkyl, aryl, or aralkyl; Each R ３ are independently selected from C1-C10 alkyl, aryl, aralkyl, or a group in which two hydrogen atoms have been removed from a C1-C10 substituted alkyl, aryl, or aralkyl; n is greater than 1.

1. A latent base catalyst comprising a substituted carbamate salt having the structure: The latent base catalyst is capable of reacting with at least one crosslinkable component of a crosslinkable resin composition via a Michael addition reaction.

2. X ＋ 10. The latent base catalyst of claim 1, wherein is selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion, a phosphonium ion, or a combination thereof.

3. X ＋ 3. The latent base catalyst according to claim 1, wherein is a quaternary ammonium cation or a phosphonium ion.

4. X ＋ is represented by the general formula NR' ４ is a quaternary ammonium cation having the formula 4. The latent base catalyst of claim 1, wherein R' is H, unsubstituted C1-C10 alkyl, substituted C1-C10 alkyl, aryl, aralkyl, or a combination thereof.

5. X ＋ is represented by the general formula NR' ４ 5. The latent base catalyst according to claim 1, wherein R′ is a C1-C4 unsubstituted alkyl.

6. The latent base catalyst according to any one of claims 1 to 5, wherein the latent base catalyst is used in an amount of 0.1 to 1.0 meq.

7. The latent base catalyst according to any one of claims 1 to 6, wherein the latent base catalyst is used in an amount of 0.01 to 0.5 meq.

8. A method for preparing a latent base catalyst capable of reacting with at least one crosslinkable component of a crosslinkable resin composition via a Michael addition reaction, comprising: providing a hydroxide-functional component; providing an excess of a multifunctional component capable of reacting with said hydroxide-functional component; The hydroxide-functional component is reacted with the component capable of reacting with the hydroxide-functional component to form a compound of general formula (I): 【Chemistry 2】 [In the formula, Each X ＋ are independently non-acidic cations, Each R １ are independently selected from H, C1-C10 alkyl, aryl, aralkyl, or C1-C10 substituted alkyl, aryl, aralkyl; Each R ２ are independently selected from C1-C10 alkyl, aryl, aralkyl, or a group in which one hydrogen has been removed from a C1-C10 substituted alkyl, aryl, or aralkyl; Each R ３ are independently selected from C1-C10 alkyl, aryl, aralkyl, or a group in which two hydrogen atoms have been removed from a C1-C10 substituted alkyl, aryl, or aralkyl; n is greater than 1. and forming a latent base catalyst having the structure: The above method, comprising:

9. 9. The method of claim 8, wherein the hydroxide-functional component is selected from a C1 to C10 alkyl ammonium hydroxide, an aryl ammonium hydroxide, an aralkyl ammonium hydroxide, or a combination thereof.

10. The method of claim 8, wherein the hydroxide-functional component is a C1 to C10 alkyl ammonium hydroxide.

11. 11. The method of claim 10, wherein the C1 to C10 alkyl ammonium hydroxide is tetrabutyl ammonium hydroxide.

12. The method of claim 8, wherein the component capable of reacting with the hydroxide-functional component is a polyfunctional isocyanate.

13. 13. The method of claim 12, wherein the polyfunctional isocyanate is selected from 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-methylene diphenyl diisocyanate, hexamethylene diisocyanate, polymethylene-polyphenyl isocyanate, homopolymers thereof, cyclic trimers thereof, cocyclic trimers thereof, and mixtures thereof.

14. 13. The method of claim 12, wherein the polyfunctional isocyanate is a hexamethylene diisocyanate trimer, a hexamethylene diisocyanate homopolymer, or a combination thereof.

15. 13. The method of claim 12, wherein any polyfunctional isocyanate that does not react with the hydroxide-functional component reacts with excess solvent in the solution.

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