Two-part (2K) water-borne coating composition

Abstract

To provide a two-part (2K) water-borne coating composition.SOLUTION: A two-part (2K) water-borne coating composition, comprises: water; and a) a binder part comprising: (a1) a hydroxyl-functional (meth)acrylate copolymer; and (a2) a non-aromatic polyester having active hydrogen groups; and b) a crosslinker part comprising: at least one polyisocyanate compound having pendant -NCO groups; and wherein the (a1) (meth)acrylate copolymer is the reaction product of a monomer mixture which comprises: i) a hydroxyl functional adduct of a monoepoxyester and an unsaturated carboxylic acid; ii) a hydroxyl functional unsaturated monomer which is different from component i); iii) an unsaturated acid functional monomer; and iv) a (meth)acrylate monomer represented by Formula H2C=CGaCO2Ra (MA).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a two-component (2K) waterborne coating composition comprising a binder part and a crosslinker part. The binder part comprises a water-reducible hydroxyl-functional (meth)acrylate copolymer and a polyester having active hydrogen groups. The crosslinker part of the composition comprises at least one polyisocyanate compound having pendant -NCO groups. The coating composition can be used as a clearcoat composition applied to vehicle finishing or refinishing. [Background technology]

[0002] Automotive refinishing refers to compositions and processes used to repair damaged automotive finishes, typically, but not necessarily, the finish provided by the original equipment manufacturer (OEM). For example, a damaged automotive part may contain a defective area where a previously applied coating layer has at least partially delaminated, potentially exposing the part's bare substrate. Thus, a refinishing operation may involve repairing or replacing the entire damaged automotive body part, repairing one or more coating layers disposed on the part, or a combination of both operations. The size of the defective area and the presence or absence of a coating layer surrounding the defective area (which, if present, may act as an anchor for the refinish coating composition) are often determining factors in the type of operation to be performed. With respect to repairing a coating layer, the refinishing process generally includes the following sequential steps: sanding the surface to be refinished; applying at least one layer of a primer composition; optionally sanding the applied primer composition; applying at least one layer of a basecoat composition to achieve a desired optical appearance, such as a desired color, gloss, or clarity of image (DOI); and applying a clearcoat composition that is sufficiently transparent or translucent to allow the underlying coating layer to show through. Historically, coating compositions used in refinishing operations, including clearcoat compositions, have been solvent-based and therefore contain large amounts of volatile organic compounds (VOCs). However, the use of such compounds is regulated. For example, in the United States, volatile organic compound emission standards are established by Section 183(e) of the Clean Air Act (Act), and reference is made to 42 United States Code (USC) §7511b(e) and 40 Code of Federal Regulations (CFR) Part 59 Subpart B for emission levels of automotive refinish coatings. In recent years, the coatings industry has made significant progress in complying with state and federal regulations regarding VOC emissions through the development of high solids solvent-borne and water-borne coating compositions. Water-based coating compositions can have desirable wetting and leveling properties for refinish applications compared to existing solvent-based alternatives, while at the same time being easy for users to apply without requiring extensive repurposing of existing application equipment. However, water-based compositions must be dehydrated for proper crosslinking and curing to occur. Due to their boiling point, water removal can be difficult to achieve by flash drying, as this traditionally requires extremely harsh baking conditions that require careful control of air movement and humidity in the oven or drying booth. Because drying of aqueous compositions can create an energy burden and can slow the refinishing process, such compositions have incorporated volatile organic co-solvents or diluents to mitigate the drying characteristics of the composition. However, if future regulations regarding the allowable levels of VOCs in automotive refinish coating compositions become more stringent, the presence of such co-solvents and diluents may become undesirable.

[0003] Therefore, it is desirable to develop water-based coating compositions that exhibit properties comparable to their solvent-based predecessors. More specifically, it is desirable that such water-based compositions exhibit good leveling at the applied surface and be dehydrated under medium or low bake conditions upon application. Furthermore, such compositions should exhibit suitable optical properties that facilitate their use in refinish applications, particularly as clear coating compositions. Further beneficial features and properties of the various compositions will become apparent from the detailed description and examples that follow. Summary of the Invention

[0004] The present disclosure provides a two-component (2K) waterborne coating composition comprising: Water and a. A binder part comprising: (a1) at least one water-dilutable hydroxyl-functional (meth)acrylate copolymer; and (a2) at least one non-aromatic polyester having active hydrogen groups; and, b) a crosslinker part comprising: at least one polyisocyanate compound having pendant -NCO groups; and, the molar ratio of active hydrogen atoms to -NCO groups in the composition is from about 5:1 to about 1:5; (a2) the non-aromatic polyester has a number average molecular weight (Mn) of about 500 to about 5000 Daltons, an acid number of about 0 to about 30 mg KOH / g, a calculated hydroxyl number of about 100 to about 600 mg KOH / g, and a calculated hydroxyl functionality of about 2 to about 8; (a1) The (meth)acrylate copolymer comprises, based on the total mass of the monomers: about 20 to about 60 wt. % of i) at least one hydroxyl-functional adduct of a monoepoxy ester and an unsaturated carboxylic acid; about 10 to about 30 wt. % of ii) at least one hydroxyl-functional unsaturated monomer different from component i); about 2 to about 6 weight percent of iii) at least one unsaturated acid-functional monomer; and about 20 to about 60% by weight of iv) at least one (meth)acrylate monomer represented by formula MA: H2C=CG a CO2R a (MA) [In the formula, G a is hydrogen, halogen or methyl; R ais C1~C 18 Alkyl; C2-C 18 Heteroalkyl; C3-C 18 cycloalkyl; C2-C8 heterocycloalkyl; C2-C8 alkenyl, or C2-C8 alkynyl; from about 0 to about 15 wt. % of v) at least one vinyl aromatic monomer; and about 0 to about 20% by weight of vi) at least one polymerizable unsaturated monomer different from i) to v); is a reaction product of monomers in the monomer mixture, comprising A two-component (2K) water-based coating composition is provided.

[0005] The present disclosure further provides cured products obtained from the two-part (2K) aqueous coating compositions. The present disclosure further provides an article comprising a metallic substrate and a multi-layer coating disposed on the metallic substrate, wherein at least one layer of the multi-layer coating comprises the cured product. In an important embodiment of the article, the multi-layer coating comprises a primer layer disposed directly on and in contact with the substrate, at least one basecoat layer comprising a color and / or visual effect imparting compound, the basecoat layer disposed directly on and in contact with the primer layer, and a clearcoat layer comprising the cured product, the clearcoat layer disposed directly on and in contact with the basecoat layer. When aspects of the present disclosure are described herein as having particular embodiments, unless otherwise stated, any one or more of the embodiments can be implemented in or combined with any one of the additional embodiments (even if the combination is not expressly stated). Expressed differently, the described embodiments are not mutually exclusive unless so stated, and permutations of the embodiments are within the scope of the present disclosure. Other objects, advantages and features of the present disclosure will become apparent to those skilled in the art upon consideration of the following discussion in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a cross-sectional side view of an article according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional side view of an article according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or its application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0003] Embodiments of the present disclosure generally relate to water-dilutable hydroxyl-functional (meth)acrylate copolymers, compositions including the same, and methods of forming the same. For the sake of brevity, conventional techniques related to the production of such polymers and compositions may not be detailed herein. Furthermore, various tasks and process steps described herein may be incorporated into more comprehensive procedures or processes having additional steps or functions not detailed herein. In particular, various steps in the production of such polymers and related compositions are well known, and therefore, for the sake of brevity, conventional steps are only briefly described herein or omitted entirely without providing well-known process details. The polymers and compositions disclosed herein may suitably comprise, consist of, or consist essentially of the components, elements, and process descriptions described herein. The embodiments illustratively disclosed herein may suitably be practiced in the absence of any element not specifically disclosed herein.

[0008] definition The term "consisting essentially of" may describe various non-limiting embodiments that do not include one or more optional compounds described herein, or one or more additives, solvents, polymers, resins, etc. not described herein but utilized in the art. The term "about" can refer in various embodiments to a value of ±0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10%. Additionally, in various non-limiting embodiments, all numerical values ​​provided herein are recognized as approximations, with endpoints or specified values ​​intended to read "about" or "approximately" the cited value, except in specific instances. Molecular weights referred to herein can typically be measured using gel permeation chromatography (GPC) using polystyrene calibration standards, such as performed in accordance with ASTM 3536. As used herein, "acid number" is the mass in milligrams of potassium hydroxide (KOH) required to neutralize one gram of the described composition. Acid number can be measured by potentiometric analysis. The term "hydroxyl number," as used herein, is defined as the mass in milligrams of potassium hydroxide required to neutralize the acetic acid incorporated in the acetylation of one gram of a chemical containing a free hydroxyl group. Hydroxyl number can be determined according to DIN 53240. The term "active hydrogen atom" refers to a hydrogen atom that exhibits activity according to the Zerewitinoff test described in Kohlerin J. Am. Chem. Soc., 49, 3181 (1927), which is expressly incorporated by reference in its entirety in various non-limiting embodiments. Active hydrogen atoms can be derived from hydroxyl, thiol, primary amine, secondary amine, and carboxyl groups. As used herein, the term softening point (°C) used herein in reference to waxes is the Ring and Ball softening point, measured according to ASTM E28 unless otherwise specified.

[0009] The viscosity of the compositions described herein is measured using a Brookfield Model CAP2000 viscometer at standard conditions of 20°C and 50% relative humidity (RH), unless otherwise specified. The viscometer is calibrated using hydrocarbon oils of known viscosities between 1 and 10,000 centipoise. Calibration is performed using an RV spindle set attached to the viscometer. Coating compositions are measured using a No. 4 spindle at 400 revolutions per minute for 1 minute until the viscometer reaches equilibrium. The viscosity corresponding to the equilibrium reading is calculated using the calibration. Unless otherwise specified, the term "particle size" refers to the largest axis of the particle. For roughly spherical particles, the largest axis is the diameter. The term "average volume particle size" (Dv50), as used herein, refers to a particle size corresponding to a particle size where 50% of the volume of sampled particles are greater than the Dv50 value and 50% of the volume of sampled particles are less than the Dv50 value. Similarly, the term "Dv90," when used, refers to a particle size corresponding to a particle size where 90% of the volume of sampled particles are less than the Dv90 value and 10% of the volume of sampled particles are greater than the Dv90 value. Particle size is measured herein by laser diffraction using an Anton Paar Particle Size Analyzer (PSA) 1190. As used herein, room temperature is 23°C plus or minus 2°C. As used herein, "ambient conditions" means the temperature and pressure in the vicinity in which the composition is located, or in which the coating layer or substrate for the coating layer is located. In the context of the present disclosure, a "two-component (2K) composition" is understood to be a composition in which the first part a) and the second part b) are stored in separate containers due to their (high) reactivity. The two parts are mixed only immediately before or during application, after which they react, usually without further activation, with bond formation and thus the formation of a polymer network. In this context, higher temperatures may be applied to accelerate the crosslinking reaction.

[0010] The term "water-dilutable (co)polymer," as used herein, refers to a (co)polymer that exists in the form of particles in water, and upon further dilution with water, the particles become dispersed or suspended and are generally stable against aggregation. In contrast to water-soluble (co)polymers, dilute solutions (about 1 g / L) of water-dilutable polymers exhibit scattering when analyzed using dynamic light scattering or any other technique known in the art of particle analysis. The term "clearcoat" is used herein to refer to a coating layer within a multi-layer coating that is sufficiently transparent or translucent to allow the underlying coating layer to show through. The term "clear" does not require absolute transparency or translucency. As used herein, "metallic" means any type of metal, metal alloy, or mixture thereof. As used herein, the term "alloy" refers to a substance composed of two or more metals or of a metal and a non-metal intimately united, usually by fusing and dissolving together when melted. As used herein, the term "catalytic amount" means a substoichiometric amount of catalyst relative to the reactants, unless otherwise specified. As used herein, the term "free radical initiator" refers to a compound that, upon exposure to sufficient energy (e.g., in the form of light or heat), decomposes into uncharged moieties, each of which has at least one unpaired electron. In particular, free radical thermal initiators generate free radicals upon activation by thermal energy, for example, upon heating or irradiation in the infrared or microwave wavelength range.

[0011] All isomeric and chiral forms of each compound described herein are expressly contemplated for use in the various non-limiting embodiments herein. It will be understood that polymer subscripts are typically written as average values ​​because the synthesis of polymers typically produces a distribution of different individual molecules.

[0012] As used herein, the term "monomer" refers to a substance that can undergo a polymerization reaction to provide a structural unit in the chemical structure of a polymer. The term "monofunctional" as used herein refers to having one polymerizable moiety. The term "multifunctional" as used herein refers to having two or more polymerizable moieties. The term "blocked," as used herein, refers to a compound having a "blocking group" such that the reactive functional group of the compound is unavailable until the blocking group is removed or decomposed. The blocking group can be selectively removed or decomposed at an appropriate point in the synthetic sequence, and the triggering event can be moisture, heat, or irradiation, among others. Examples of blocked isocyanates include isocyanates co-reacted with phenol, methyl ethyl ketoxime, or ε-caprolactam. The term "fatty acid," as used herein, refers to a monocarboxylic acid composed of an aliphatic chain containing 4 to 22 carbon atoms and having a terminal carboxyl group (COOH). Fatty acids can be saturated or unsaturated, branched or unbranched, and may or may not contain one or more hydroxyl groups. Exemplary fatty acids include linoleic acid; oleic acid; stearic acid; palmitic acid; dihydroxystearic acid; linolenic acid; and eicosanoic acid. The term "dimeric fatty acid" is interchangeable with "dimerized fatty acid" and refers to a compound containing two fatty acid subunits whose respective fatty acid side chains are shared with each other via a bond or linking group. Thus, as described herein, a dimer of dimeric fatty acid is a covalent fatty acid dimer. Dimeric fatty acids can be heterodimers or homodimers and can be cyclic or acyclic. This term is intended to encompass derivatives of dimeric fatty acids having functional carboxyl groups that function substantially similarly to dicarboxylic acids in reactions with glycols and diols to form polyesters, including esters and ester-forming reactive derivatives, such as acid halides and acid anhydrides. As used herein, "(meth)acryl" is an abbreviation for "acryl" and / or "methacryl." Thus, the term "(meth)acrylamide" collectively refers to acrylamide and methacrylamide. As used herein, "C1-C n "Alkyl" refers to a monovalent group or moiety having 1 to n carbon atoms that is a radical of an alkane, including straight-chain and branched organic groups. Thus, "C1-C 18 "Alkyl" refers to a monovalent group or moiety having 1 to 18 carbon atoms, which is a radical of an alkane, including straight-chain and branched organic groups. Examples of alkyl groups include methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; sec-butyl; tert-butyl; n-pentyl; n-hexyl; n-heptyl; and 2-ethylhexyl. In this disclosure, such alkyl groups can be unsubstituted or substituted with one or more halogens. When applicable to a given moiety (R), permissible one or more non-halogen substituents in an alkyl group are described herein. Term “C1~C 18 "Hydroxyalkyl," as used herein, refers to an HO-(alkyl) group having 1 to 18 carbon atoms, where the point of attachment of the substituent is through the oxygen atom and the alkyl group is as defined above. "Alkoxy group" refers to a monovalent group represented by -OA, where A is an alkyl group, non-limiting examples of which are methoxy, ethoxy, and isopropyloxy. 18 "Alkoxyalkyl," as used herein, refers to an alkyl group or moiety having an alkoxy substituent, as defined above, wherein the (alkyl-O-alkyl) portion has a total of 1 to 18 carbon atoms; such groups include methoxymethyl (-CHOCH), 2-methoxyethyl (-CHCHOCH), and 2-ethoxyethyl. Similarly, the term "C7-C 18"Alkoxyaryl," as used herein, refers to an aryl group having an alkoxy substituent, as defined above, wherein the (aryl-O-alkyl) portion contains a total of 7 to 18 carbon atoms. The term "C2-C4 alkylene," as used herein, is defined as a saturated divalent hydrocarbon radical having from two to four carbon atoms. The term “C3~C 18 "Cycloalkyl" includes saturated monocyclic or polycyclic hydrocarbon groups or moieties having 3 to 18 carbon atoms. In this disclosure, such cycloalkyl groups or moieties can be unsubstituted or substituted with one or more halogens. Permissible values ​​for one or more non-halogen substituents in a cycloalkyl group, when applicable to a given moiety (R), are described herein. Examples of cycloalkyl groups include cyclopropyl; cyclobutyl; cyclopentyl; cyclohexyl; cycloheptyl; cyclooctyl; adamantane; and norbornane. As used herein, "C2-C 18 "Alkenyl" refers to a hydrocarbyl group or moiety having 2 to 18 carbon atoms and at least one unit of ethylenic unsaturation. Alkenyl groups or moieties can be straight-chained, branched, or cyclic and can be optionally substituted with one or more halogens. Permissible non-halogen substituents in an alkenyl group, when applicable to a given moiety (R), are described herein. The term "alkenyl" also encompasses radicals having "cis" and "trans" configurations, or alternatively, "E" and "Z" configurations, as recognized by those skilled in the art. C2-C 20 Examples of alkenyl groups include -CH=CH2; -CH=CHCH3; -CH2CH=CH2; -C(=CH2)(CH3); -CH=CHCH2CH3; -CH2CH=CHCH3; -CH2CH2CH=CH2; -CH=C(CH3)2; -CH2C(=CH2)(CH3); -C(=CH2)CH2CH3; -C(CH3)=CHCH3; -C(CH3)CH=CH2; -CH=CHCH2CH2CH3; -CH2CH=CHCH2CH 3;-CH2CH2CH=CHCH3;-CH2CH2CH2CH=CH2;-C(=CH2)CH2CH2CH3;-C(CH3)=CHCH2CH3;-CH(CH3)CH=CHCH ; -CH(CH3)CH2CH=CH2; -CH2CH=C(CH3)2; 1-cyclopent-1-enyl; 1-cyclopent-2-enyl; 1-cyclopent-3-enyl; 1-cyclohex-1-enyl; 1-cyclohex-2-enyl; and 1-cyclohexyl-3-enyl. As used herein, "C-C alkyl" used alone or as part of a longer moiety (as in "aralkyl group") refers to a C-C alkyl group. 18 "Aryl" refers to monocyclic, bicyclic, and tricyclic ring systems in which the monocyclic ring is aromatic or at least one ring in the bicyclic or tricyclic ring system is aromatic. Bicyclic and tricyclic ring systems include benzo-fused 2- to 3-membered carbocyclic rings. In the present disclosure, such aryl groups can be unsubstituted or substituted with one or more halogens. Permissible values ​​for one or more non-halogen substituents in an aryl group, when applicable to a given moiety (R), are described herein. Exemplary aryl groups include phenyl; (C1-C4) alkylphenyl, e.g., tolyl and ethylphenyl; indenyl; naphthalenyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl; and anthracenyl. As used herein, "alkylaryl" refers to an alkyl-substituted aryl group or moiety, and "substituted alkylaryl" refers to an alkylaryl group or moiety further bearing one or more substituents as defined above. Additionally, as used herein, "aralkyl" refers to an alkyl group or moiety substituted with an aryl radical, as defined above. The term "hetero," as used herein, refers to groups or moieties that contain one or more heteroatoms, such as N, O, Si, and S. Thus, for example, "heterocyclic" refers to cyclic groups that have, for example, N, O, Si, or S as part of the ring structure. "Heteroalkyl," "heterocycloalkyl," and "heteroaryl" moieties are alkyl, cycloalkyl, and aryl groups, as defined herein above, that contain N, O, Si, or S as part of their structure, respectively.

[0013] The term "non-polymeric" is used herein as a descriptor for compounds that are not composed of repeating structural units. A non-polymeric compound can be considered a unique, single structural unit. The term "non-aromatic," as applied herein as a descriptor of a monomer, refers to a compound that does not have an aromatic nucleus. The term is intended to include both aliphatic and cycloaliphatic compounds, which may be saturated or unsaturated and, if unsaturated, may contain non-aromatic carbon-carbon double or triple bonds. Non-aromatic polymeric compounds are substantially free of aromatic nuclei in their backbones, such that the polymer may contain aromatic nuclei only through the technical impurity of aliphatic or cycloaliphatic monomeric building blocks. The term "base," as used herein, refers to a species that can abstract a proton in either a polar or non-polar solvent; or a hydroxide anion (OH - ) means a species that can donate In various embodiments, the term "free of" describes embodiments that contain less than about 5, 4, 3, 2, 1, 0.5, or 0.1% by weight of the component, compound, moiety, functional group, element, or ion of interest, using appropriate weight standards understood by those of skill in the art. In other embodiments, the term "free of" describes embodiments that contain less than about 0% by weight of the component, compound, moiety, functional group, element, or ion of interest. The term "anhydrous" as used herein is equivalent to "free from water."

[0014] Again, the aqueous composition includes water, a) a binder part, and b) a crosslinker part. The water can be present in an amount of 30 to 80% by weight, based on the weight of the composition. For example, the water can be present in an amount of 35 to 70%, 40 to 60%, 45 to 55%, 45 to 52%, or 46 to 51% by weight. At this water content, drying and coalescence of the composition when applied to a substrate may not involve high energy and time costs. Compositions with this water content can have, for example, a viscosity of less than 500 centipoise, less than 200 centipoise, less than 100 centipoise, less than 50 centipoise, less than 40 centipoise, or less than 30 centipoise, measured at room temperature. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. The water of a two-part (2K) composition need not be added separately to one or more of the components or to the composition itself. Alternatively, one or more of the components of the composition may be provided in water.

[0015] In certain embodiments, the binder part a) of the two-component (2K) composition contains water, such that the binder part a) provides at least a portion of the water of the two-component (2K) composition. However, it is not excluded to add additional water to the composition during or after combining the water-containing binder part a) with the crosslinker part b). The addition of this additional water may serve to reduce the viscosity of the composition, which may be useful for certain methods described below in which the composition is applied to a substrate, such as spraying.

[0016] Part a) Referring now to the binder part a) of the two-part aqueous composition, this part comprises: (a1) at least one water-dilutable hydroxyl-functional (meth)acrylic copolymer; and (a2) at least one non-aromatic polyester having active hydrogen groups. The at least one hydroxyl-functional (meth)acrylate copolymer of component (a1) is water-dilutable but typically compatible with polyisocyanates, particularly hydrophobic polyisocyanates that are not hydrophilically modified with polyether or polyester groups. Thus, the two-component coating composition is water-dilutable, providing operators with flexibility when applying the coating composition, for example, in vehicle refinishing operations. Furthermore, the aforementioned amount of vinyl aromatic monomer is believed to promote the miscibility of the hydroxyl-functional (meth)acrylate copolymer with polyisocyanates, thereby maintaining the dispersion stability of the copolymer and improving the appearance of the final cured coating. The presence of the non-aromatic polyester in the binder part of the composition improves the appearance of the cured coating obtained from the composition. The non-aromatic polyester may also contribute to the cured coating exhibiting weatherability.

[0017] Copolymer component (a1) The (meth)acrylate copolymer is the reaction product of a monomer mixture, which monomer mixture comprises, based on the total weight of the monomers in the monomer mixture: 20 to 60% by weight of i) at least one hydroxyl-functional adduct of a monoepoxy ester with an unsaturated carboxylic acid; 10 to 30% by weight of ii) at least one hydroxyl-functional unsaturated monomer different from component i); 2-6 wt. % of iii) at least one unsaturated acid-functional monomer; 20 to 60% by weight of iv) at least one (meth)acrylate monomer represented by the formula MA: H2C=CG a CO2R a (MA) [In the formula, G a is hydrogen, halogen or methyl; R a is C1~C 18 Alkyl; C2-C 18 Heteroalkyl; C3-C 18cycloalkyl; C2-C8 heterocycloalkyl; C2-C8 alkenyl, or C2-C8 alkynyl; 0 to 15% by weight of v) at least one vinyl aromatic monomer; and vi) 0 to 20 mass % of at least one polymerizable unsaturated monomer different from the monomer components i) to v).

[0018] Monomer component i) : Hydroxyl functional adducts The monomer mix comprises 20 to 60 weight percent of i) at least one hydroxyl-functional adduct of a monoepoxy ester and an unsaturated carboxylic acid, based on the total weight of the monomers in the monomer mix. For example, the monomer mix can comprise 30 to 60 weight percent or 40 to 60 weight percent of i) at least one adduct, based on the total weight of the monomers in the monomer mix. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Typically, the adducts are formed by the nucleophilic addition reaction of a monoepoxy ester with a hydroxyalkyl ester in its acid form. This acidotic ring-opening reaction traditionally requires a catalyst, examples of which include tertiary amines, quaternary ammonium compounds, and transition metal compounds. The monoepoxy ester reactant is typically a glycidyl ester derived from an aliphatic saturated monocarboxylic acid having a tertiary or quaternary carbon atom in the alpha (α-) position. Representative monoepoxy ester reactants are glycidyl esters of saturated α,α-dialkylalkane-monocarboxylic acids having 5 to 13 carbon atoms or 9 to 11 carbon atoms in the acid molecule. Exemplary monoepoxy ester reactants include versatic acid glycidyl ester, available commercially as Cardura E10 from Hexion; pivalic acid glycidyl ester, available commercially as Cardura E5 from Hexion; and the reaction product of a tertiary fatty acid of up to 12 carbon atoms with epichlorohydrin. The acid-functional reactant compound can be an aliphatic unsaturated monocarboxylic acid, non-limiting examples of which include α,β-monoethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and isocrotonic acid; C1-C6 alkyl half esters of α,β-monoethylenically unsaturated dicarboxylic acids such as fumaric acid and maleic acid; and C1-C6 alkyl esters of α,β-monoethylenically unsaturated tricarboxylic acids having one free carboxylic acid group. In various embodiments, the acid-functional reactant compound is acrylic acid and / or methacrylic acid.

[0019] Monomer component ii) : Hydroxyl-functional ethylenically unsaturated monomers The monomer mix comprises 10 to 30 weight percent ii) of at least one hydroxyl-functional monomer different from monomer component i), based on the total weight of the monomers in the monomer mix. For example, the monomer mix can comprise 10 to 25 weight percent or 10 to 20 weight percent ii) of at least one hydroxyl-functional monomer, based on the total weight of the monomers in the monomer mix. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Exemplary component ii) monomers include hydroxyalkyl esters having a primary or secondary hydroxyl group derived from α,β-monoethylenically unsaturated monocarboxylic acids, such as hydroxyalkyl esters derived from acrylic acid, methacrylic acid, crotonic acid, or isocrotonic acid. In one embodiment, monomer component ii) comprises at least one hydroxyl (meth)acrylate monomer represented by the formula HMA: H2C=CG a CO2R h (HMA) In the formula, G a is hydrogen, halogen or methyl; R h is C1~C 18 It is a hydroxyalkyl. Typical monomers according to the formula HMA are G a is hydrogen, halogen or methyl; R h However, C1~C 12 It is a hydroxyalkyl monomer. a is hydrogen or methyl, and R h Monomers in which is a C1-C6 hydroxyalkyl can also be used. Examples of (meth)acrylate monomers according to the formula HMA include hydroxyethyl (meth)acrylate; 1-hydroxypropyl (meth)acrylate; 2-hydroxypropyl (meth)acrylate; 1-hydroxybutyl (meth)acrylate; 2-hydroxybutyl (meth)acrylate; and 3-hydroxybutyl (meth)acrylate.

[0020] Monomer component iii) : Ethylenically unsaturated acid functional monomer The monomer mix also includes 2-6 wt. % iii) of at least one ethylenically unsaturated acid-functional monomer, based on the total weight of the monomers in the monomer mix. For example, component iii) can comprise 2-5 wt. % or 2-4 wt. % of the monomer mix. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Although not intending to limit the disclosure, the unsaturated acid-functional monomer is selected from ethylenically unsaturated carboxylic acids, ethylenically unsaturated sulfonic acids, vinylphosphonic acids, and mixtures thereof. Suitable ethylenically unsaturated sulfonic acids include, for example, vinyl sulfonic acid, styrene sulfonic acid, and acrylamidomethylpropane sulfonic acid. Typically, monomer component iii) comprises at least one ethylenically unsaturated carboxylic acid selected from α,β-monoethylenically unsaturated monocarboxylic acids, α,β-monoethylenically unsaturated dicarboxylic acids, C1-C6 alkyl half esters of α,β-monoethylenically unsaturated dicarboxylic acids, α,β-monoethylenically unsaturated tricarboxylic acids, C1-C6 alkyl esters of α,β-monoethylenically unsaturated tricarboxylic acids having at least one free carboxylic acid group, and mixtures thereof. In particular, monomer component iii) may comprise at least one ethylenically unsaturated carboxylic acid selected from methacrylic acid, acrylic acid, itaconic acid, maleic acid, aconitic acid, crotonic acid, fumaric acid, and mixtures thereof. For the sake of completeness, the unsaturated acid-functional monomers mentioned above can be used in the form of their free acids, but this does not exclude that the acid groups of the constituent monomers can be partially or completely neutralized with a suitable base, as long as their participation in the copolymerization reaction is not impaired.

[0021] Monomer component iv) (Meth)acrylate monomer of formula MA The monomer mixture also includes 20 to 60 weight percent, based on the total weight of the monomers in the monomer mixture, of iv) at least one (meth)acrylate monomer represented by the formula MA: H2C=CG a CO2R a (MA) In the formula, G a is hydrogen, halogen or methyl; R a is C1~C 18 Alkyl; C2-C 18 Heteroalkyl; C3-C 18 cycloalkyl; C2-C8 heterocycloalkyl; C2-C8 alkenyl; or C2-C8 alkynyl. For example, the monomer mix can include 25 to 50 weight percent, based on the total weight of the monomers in the monomer mix, of iv) at least one (meth)acrylate monomer having the formula MA. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. In a typical monomer according to the formula MA: a is hydrogen, halogen or methyl; R a is C1~C 18 Alkyl or C3-C 18 It is a cycloalkyl. G a Monomers in which is hydrogen or methyl can also be used. (Meth)acrylate monomers according to formula MA may be used alone or in combination, and examples thereof include methyl (meth)acrylate; ethyl (meth)acrylate; n-butyl (meth)acrylate; isobutyl (meth)acrylate; hexyl (meth)acrylate; 2-ethylhexyl (meth)acrylate; isodecyl (meth)acrylate; dodecyl (meth)acrylate; lauryl (meth)acrylate; stearyl (meth)acrylate; cyclohexyl (meth)acrylate; 3,3,5-trimethylcyclohexyl (meth)acrylate; Examples include 4-tert-butylcyclohexyl (meth)acrylate; isobornyl (meth)acrylate; norbornyl (meth)acrylate; dihydrodicyclopentadienyl (meth)acrylate; ethylene glycol monomethyl ether (meth)acrylate; ethylene glycol monoethyl ether (meth)acrylate; ethylene glycol monododecyl ether (meth)acrylate; diethylene glycol monomethyl ether (meth)acrylate; trifluoroethyl (meth)acrylate; and perfluorooctyl (meth)acrylate. The (meth)acrylate monomers comprising component iv) of the monomer mixture may, in some embodiments, include "hard" monomers. The term "hard monomer" typically refers to a monomer that, when homopolymerized, produces a homopolymer having a glass transition temperature (Tg) greater than about 30° C. For example, monomer component iv) may include at least one (meth)acrylate monomer that is considered a hard monomer. Exemplary hard monomers include cyclohexyl (meth)acrylate; 3,3,5-trimethylcyclohexyl (meth)acrylate; isobornyl (meth)acrylate; norbornyl (meth)acrylate; dihydrodicyclopentadienyl (meth)acrylate; and 4-tert-butylcyclohexyl (meth)acrylate.

[0022] Monomer component v) Optional vinyl aromatic monomer The monomer mix may also include 0 to 15 weight percent (v) of at least one vinyl aromatic monomer, based on the total weight of the monomers in the monomer mix. For example, the monomer mix may include 4 to 14 weight percent, 8 to 14 weight percent, or 10 to 14 weight percent (v) of at least one vinyl aromatic monomer, based on the total weight of the monomers in the monomer mix. Alternatively, this monomer may be excluded entirely. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. In one embodiment, the monomer component v) comprises at least one vinyl aromatic monomer of formula (VA): [ka] In the formula, R 1 is H or C1-C4 alkyl; Each R 2 are independently hydrogen or C1-C4 alkyl; Ar is unsubstituted phenyl or phenyl substituted with 1 to 5 substituents, each of which is independently halogen or C1-C4 alkyl; n is an integer of 0 to 4. Typical monomers according to formula VA are R 1 is H or methyl; each R 2 are independently H or methyl; Ar is unsubstituted phenyl or phenyl substituted with 1 to 5 substituents, each substituent being independently halogen or C1-C4 alkyl; and n is 0 or 1. Vinyl aromatic monomers according to formula (VA) may be used alone or in combination and include, for example, styrene; α-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 2-tert-butylstyrene; 4-tert-butylstyrene; 2-chlorostyrene; and 4-chlorostyrene.

[0023] Monomer component vi) Optional further monomers The monomer mixture can also include 0 to 25% by weight, based on the total weight of the monomers in the monomer mixture, of at least one polymerizable unsaturated monomer different from monomer components i) to v). For example, the monomer mixture can include 0 to 20%, 1 to 20%, or 5 to 20% by weight, based on the total weight of the monomers in the monomer mixture, of at least one polymerizable unsaturated monomer different from monomer components i) to v). In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. The monomers of component vi) may be used alone or in combination, and examples thereof include aromatic (meth)acrylate monomers; (meth)acrylate-functionalized oligomers; nitrogen (N-)-functionalized ethylenically unsaturated monomers; silane-functional ethylenically unsaturated monomers such as methacryloxypropyltri(C1-C5)alkoxysilane and vinyltri(C1-C5)alkoxysilane; acetoacetyl-functional unsaturated monomers such as acetoacetoxyethyl methacrylate; vinyl esters; vinyl and vinylidene halides; vinyl ethers; alkyl vinyl ketones; cycloalkyl vinyl ketones; heterocyclic aliphatic vinyl compounds; poly(meth)acrylates of alkane polyols; poly(meth)acrylates of oxyalkane polyols; and poly(C2-C3) alkylene glycol di(meth)acrylates. Suitable aromatic (meth)acrylate monomers include those represented by formula AII: H2C=CG b CO2R b (AII) In the formula, G b is hydrogen, halogen or methyl; R b C6~C 18 Aryl, C1-C9 heteroaryl, C7-C 18 Alkoxyaryl, C7-C 18 Alkaryl or C7-C 18 It is aralkyl. (Meth)acrylate monomers according to formula (AII) may be used alone or in combination, and examples thereof include benzyl (meth)acrylate; phenoxyethyl (meth)acrylate; and phenoxypropyl (meth)acrylate. Suitable (meth)acrylate-functionalized oligomers can be selected from (meth)acrylate-functionalized polyurethanes, (meth)acrylate-functionalized polybutadienes, (meth)acrylic polyol (meth)acrylates, polyester (meth)acrylate oligomers, polyamide (meth)acrylate oligomers, polyether (meth)acrylate oligomers, and mixtures thereof. The oligomers can have one or more acrylate and / or methacrylate groups attached to the oligomer backbone, and the (meth)acrylate functional groups can be at the terminal positions of the oligomer and / or distributed along the oligomer backbone. Typically, the (meth)acrylate-functionalized oligomers reacting as monomers in the derivation of copolymer (a1) have two or more (meth)acrylate functional groups per molecule; and / or have a weight average molecular weight (Mw) of about 300 to about 1,000 Daltons. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the recited values ​​and therebetween, are expressly contemplated for use herein.

[0024] With respect to (N-) functionalized ethylenically unsaturated monomers, the nitrogen-functionalized group may be either a nitrile or urea, or may contain an imide, amide, or amine nitrogen atom. Examples of nitrile monomers include acrylonitrile and methacrylonitrile. Exemplary maleimide monomers include maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide. Exemplary (meth)acrylamides include acryloylmorpholine; diacetone (meth)acrylamide; N-methyl (meth)acrylamide; N-ethyl (meth)acrylamide; N-isopropyl (meth)acrylamide; Nt-butyl (meth)acrylamide; N-hexyl (meth)acrylamide; N-cyclohexyl (meth)acrylamide; N-octyl (meth)acrylamide; Nt-octyl (meth)acrylamide; N-dodecyl (meth)acrylamide; N-benzyl (meth)acrylamide; N-(hydroxymethyl)acrylamide; N-isobutoxymethyl acrylamide; N-butoxymethyl acrylamide; N,N-dimethyl (meth)acrylamide; N,N-diethyl (meth)acrylamide. Examples of suitable acrylamides include acrylamide; N,N-propyl(meth)acrylamide; N,N-dibutyl(meth)acrylamide; N,N-dihexyl(meth)acrylamide; N,N-dimethylaminomethylacrylamide; N,N-dimethylaminoethylacrylamide; N,N-dimethylaminopropylacrylamide; N,N-dimethylaminohexylacrylamide; N,N-diethylaminomethylacrylamide; N,N-diethylaminoethylacrylamide; N,N-diethylaminopropylacrylamide; N,N-dimethylaminohexylacrylamide; N-hydroxymethyl(meth)acrylamide; acrylamido-2-methylpropanesulfonate; and N,N'-methylenebisacrylamide. It is not excluded that the copolymer (a1) contains residues of at least one amino(meth)acrylate monomer. As used herein, the term "amino(meth)acrylate" refers to a derivative of methacrylic acid or acrylic acid having a primary, secondary, or tertiary amino group; the amino group may be part of a linear, branched, or cyclic aliphatic or aromatic group. The at least one amino(meth)acrylate monomer may be a tertiary amino(meth)acrylate, such as, in particular, an N,N-dialkylaminoalkyl(meth)acrylate. In various embodiments, one or more of N,N-dimethylaminoethyl methacrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl methacrylate, or N,N-dimethylaminopropyl acrylate may be used.

[0025] In a further non-limiting embodiment, the monomer mixture includes at least one vinyl monomer having a nitrogen heterocyclic structure. Exemplary heterocyclic structures have either five or six members and may contain oxygen atoms in addition to nitrogen; the five- or six-membered ring may represent, for example, a pyridine, pyrimidine, pyridazine, imidazoline, imidazole, oxazoline, oxazole, or morpholine ring. Examples (used alone or in combination) include N-vinylcaprolactam (NVC); vinylmethyloxazolidinone (VMOX); N-vinylformamide; N-vinylcarbazole; N-vinylacetamide; and N-vinylpyrrolidone. Exemplary vinyl esters that may be copolymerized in the present disclosure include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and the VEOVA™ series of monomers available from Shell Chemical Company. Examples of poly(meth)acrylates of alkane polyols that may be copolymerized include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. Examples of poly(meth)acrylates of oxyalkane polyols that can be copolymerized include diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dibutylene glycol di(meth)acrylate, and di(pentamethylene glycol) dimethacrylate.

[0026] In one embodiment, the monomer mixture comprises at least one monomer having the general formula AM1: R 4 -C(H)=C(R 5 )-A-(R 6 O) [a] -R 7 (AM1) In the formula, R 4 is H, methyl, CO2H or CH2CO2H; R 5 is hydrogen, halogen or methyl; A is -CH2C(O)O-, -C(O)O-, -O-, -CH2O-, -CH2C(O)N-, -C(O)N-, -CH2-, -OC(O)-, -NHC(O)O-, -NHC(O)NH-, -C6H4(R 8 )-NH-C(O)-O-, -C6H4(R 8)-NH-C(O)-NH-, -C(O)O-CH2-CH(CH2OH)-O-, -C(O)O-CH2-CH(CH2OH)-NH-, -C(O)O-CH2-CH2-CH(OH)-O-, -C(O)O-CH2-CH2-CH(OH) -NH-, -CH2-O-CH2-CH(CH2OH)-O-, -CH2-O-CH2-CH2-CH(OH)-O-, -CH2-O-CH2-CH(CH2OH)-NH-, or -CH2-O-CH2-CH2-CH(OH)-NH-; Each R 6 are independently C2-C4 alkylene; [a] has a value of 5 to 100; R 7 is C1~C 30 Alkyl, C1-C 30 Hydroxyalkyl, C1-C 30 Aminoalkyl, C3-C 18 Cycloalkyl, C2-C5 heterocycloalkyl, C2-C 20 Alkenyl, C2-C 12 Alkynyl, C6-C 18 Aryl, C7-C 24 Alkaryl or C7-C 24 is aralkyl; and R 8 is —CH— or —(C)(CH)—. A typical monomer according to formula AM1 is R 4 is H, methyl, COH or CHCOH; R 5 is hydrogen, halogen, or methyl; A is —CHC(O)O— or —C(O)O—; and each R 6 are independently C2-C4 alkylene; [a] has a value of 10 to 30; and R 7 But C6~C 30 Alkyl, C6-C 30 Hydroxyalkyl, C6-C 30 Aminoalkyl, C3-C 18 Cycloalkyl, C6-C 18 Aryl, C7-C 18 Alkaryl or C7-C 18 It is an aralkyl monomer. Representative monomers according to formula AM1 are R 4 is H, methyl, COH or CHCOH; R 5 is hydrogen, halogen, or methyl; A is —C(O)O—; and each R 6 are independently C2-C3 alkylene; [a] has a value of 10 to 30; and R 7 But C6~C 30 Alkyl, C6-C 30 Hydroxyalkyl or C6-C 30 It is an aminoalkyl monomer. Monomers according to formula AM1 may be copolymerized alone or in combination, examples of which include lauryl ethoxylate[a](meth)acrylate; cetyl ethoxylate[a](meth)acrylate; stearyl ethoxylate[a](meth)acrylate; behenyl ethoxylate[a](meth)acrylate; lauryl ethoxylate[a]itaconate; cetyl ethoxylate[a]itaconate; stearyl ethoxylate[a]itaconate; behenyl ethoxylate[a]itaconate; lauryl ethoxylate[a]maleate; cetyl ethoxylate[a]maleate; stearyl ethoxylate[a]maleate; and behenyl ethoxylate[a]maleate, where [a] is the number of moles of ethoxylation and has a value of 10 to 30. In other words, each of the above can be described as an ethoxylated compound having a degree of ethoxylation of 10 to 30 moles of ethylene oxide. Parameter [a] can, in certain embodiments, have a value of 15 to 30 or 15 to 25. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein.

[0027] Hydroxy-functional (meth)acrylic copolymers are typically produced by free-radical solution copolymerization, in which a solution of the monomers is prepared in a solvent that also dissolves the copolymer, and the monomers are polymerized by free-radical polymerization in the presence of a free-radical initiator. Broadly speaking, the monomers are typically charged to a reflux reactor in the presence of at least one organic solvent and a free-radical initiator. While the concentration of the monomers in the solution can vary, a weight ratio of monomer to solvent of 1:20 to 2:1, e.g., 1:2 to 1.5:1, is typical. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Conventional polymerization conditions are typically utilized, including temperatures ranging from 25 to 250°C, e.g., 50 to 250°C or 75 to 250°C. The polymerization pressure is generally not critical, and thus the polymerization may be carried out at subatmospheric, atmospheric, or superatmospheric pressures. The polymerization may be carried out under the exclusion of oxygen, if desired; the reaction vessel may be blanketed with an inert, dry gas, such as, for example, nitrogen, helium, argon, etc. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of and between the recited values, are expressly contemplated for use herein.

[0028] Conventionally, at least one radical initiator is utilized in an amount of 0.1 to 1 weight percent, e.g., 0.1 to 0.5 weight percent, based on the total weight of polymerizable monomers. In various non-limiting embodiments, all values ​​and ranges of values, both whole and fractional, inclusive, are expressly contemplated for use herein. An exemplary class of suitable free radical initiators is organic peroxides, for example selected from: cyclic peroxides, diacyl peroxides, dialkyl peroxides, hydroperoxides, peroxycarbonates, peroxydicarbonates, peroxyesters, and peroxyketals. The free radical initiator may be known in the art. For example, the free radical initiator may include hydrogen peroxide. Alternatively, the free radical initiator may include an organic hydroperoxide. For completeness, included within the definition of hydroperoxide are materials such as organic peroxides or organic peresters that decompose or hydrolyze to generate organic hydroperoxides in situ; examples of such peroxides and peresters are cyclohexyl and hydroxycyclohexyl peroxide, respectively, and t-butyl perbenzoate. In one embodiment of the present disclosure, the free radical initiator comprises at least one hydroperoxide compound represented by the formula: R p OOH In the formula, R p is an aliphatic or aromatic group containing up to 18 carbon atoms, typically R p is C1~C 12 Alkyl, C6-C 18 Aryl or C7-C 18 It is aralkyl. The one or more free radical initiators may include cumene hydroperoxide (CHP); para-menthane hydroperoxide; t-butyl hydroperoxide (TBH); t-butyl perbenzoate; t-butyl peroxypivalate; di-t-butyl peroxide; t-butyl peroxyacetate; t-butyl peroxy-2-hexanoate; t-amyl hydroperoxide; 1,2,3,4-tetramethylbutyl hydroperoxide; benzoyl peroxide; dibenzoyl peroxide; 1,3 -bis(t-butylperoxyisopropyl)benzene; diacetyl peroxide; butyl 4,4-bis(t-butylperoxy)valerate; p-chlorobenzoyl peroxide; t-butylcumyl peroxide; di-t-butyl peroxide; dicumyl peroxide; 2,5-dimethyl-2,5-di-t-butylperoxyhexane; 2,5-dimethyl-2,5-di-t-butyl-peroxyhex-3-yne; and 4-methyl-2,2-di-t-butylperoxypentane.

[0029] Azo polymerization initiators may also be used and may be selected from the group consisting of azonitriles; azoesters; azoamides; azoamidines; azoimidazolines; macroazo initiators; and combinations thereof. Examples of suitable azo polymerization initiators include 2,2'-azobis(2-methylbutyronitrile); 2,2'-azobis(isobutyronitrile); 2,2'-azobis(2,4-dimethylvaleronitrile); 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile); 1,1'-azobis(cyclohexane-1-carbonitrile); 4,4'-azobis(4-cyanovaleric acid); dimethyl 2,2'-azobis(2-methylpropionate); 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]; 2,2'-azobis(N-butyl-2-methylpropionamide); 2,2'-azobis[2-(2-imidazoline-2-yl)propionamide]; 2,2'-Azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride; 2,2'-Azobis(2-methylpropionamidine) dihydrochloride; 2,2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine] tetrahydrate; 4,4-Azobis(4-cyanovaleric acid) polymer with α,ω-bis(3-aminopropyl)polydimethylsiloxane (VPS-1001, available from Wako Pure Chemical Industries, Ltd.); and 4,4'-Azobis(4-cyanopentanoic acid)·polyethylene glycol polymer (VPE-0201, available from Wako Pure Chemical Industries, Ltd.). Redox initiators can also be used, which include a combination of an oxidizing agent and a reducing agent. Suitable oxidizing agents can be selected from cyclic peroxides, diacyl peroxides, dialkyl peroxides, hydroperoxides, peroxycarbonates, peroxydicarbonates, peroxyesters, peroxyketals, and mixtures thereof. Corresponding reducing agents can be selected from alkali metal sulfites; alkali metal bisulfites; alkali metal metabisulfites; formaldehyde sulfoxylates; alkali metal salts of aliphatic sulfinic acids; alkali metal hydrogen sulfides; salts of polyvalent metals, particularly Co(II) salts and Fe(II) salts, such as iron(II) sulfate, ammonium iron(II) sulfate, or iron(II) phosphate; dihydroxymaleic acid; benzoin; ascorbic acid; reducing sugars, such as sorbose, glucose, fructose, and / or dihydroxyacetone; and mixtures thereof.

[0030] Free radical polymerization may be carried out in the presence of a chain transfer agent, which acts to transfer free radicals, reducing the molecular weight of the resulting polymer and / or controlling chain propagation in the polymerization. When added, the chain transfer agent may comprise 0.01 to 1 weight percent of the mixture, based on the total weight of polymerizable monomers. The amount of polymerization initiator and any chain transfer agent present contributes to the number average molecular weight of the (co)polymer, as does the choice of solvent. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein.

[0031] Free radical polymerization reactions are typically carried out in an organic solvent, typically a polar solvent. Useful polar solvents may have a boiling point of at least 20°C, e.g., at least 30°C, or at least 40°C, measured at 1 atmosphere (1.01325 bar). Such polar solvents may be used alone or in combination, and examples include C1-C8 alkanols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, and isobutanol; acetonitrile; N,N-di(C1-C4) alkyl acyl amides, such as N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAc); hexamethylphosphoric triamide; N-methylpyrrolidone; pyridine; esters, such as (C1-C8) alkyl acetates, esters, and the like. Examples of suitable solvents include acetone, ethyl ketone, methyl ethyl ketone (2-butanone), and methyl isobutyl ketone; ethers such as tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), and 1,2-dimethoxyethane; 1,3-dioxolane; dimethyl sulfoxide (DMSO); and dichloromethane (DCM). In an exemplary embodiment, the polymerization reaction is carried out in the presence of a (C1-C8) alkyl acetate, such as ethyl acetate.

[0032] The hydroxyl-functional (meth)acrylate copolymer (a1) may be prepared from a monomer mixture by a skew feed polymerization method using at least two monomer feed streams. In one embodiment, the first feed stream comprises: I) 60 to 100 weight percent of a hydroxyl-functional adduct of a monoepoxy ester and an unsaturated carboxylic acid i, based on the total amount of component i) in the monomer mixture; II) 0 to 60 weight percent of a hydroxyl-functional unsaturated monomer ii, based on the total amount of monomers ii) in the monomer mixture; III) 0 to 30 weight percent of an unsaturated acid-functional monomer iii, based on the total amount of monomers iii) in the monomer mixture; and IV) 0 to 80 weight percent of at least one (meth)acrylate monomer represented by formula MA, based on the total amount of monomers iv) in the monomer mixture; V) 0 to 100 weight percent of at least one vinyl aromatic monomer, based on the total amount of monomers v) in the monomer mixture; and VI) 0 to 100 weight percent of other polymerizable unsaturated monomers vi), based on the total amount of monomers vi) in the monomer mixture. The remaining one or more feed streams comprise the remainder of monomer components i) to vi). In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the recited values ​​and therebetween, are expressly contemplated for use herein.

[0033] In such skew-feed polymerizations, the total amount of free radical initiator added may be introduced entirely at the beginning of the first feed step. However, it is more common for the free radical initiator to be introduced in portions over time, particularly with a portion in each feed stream. Each initiator portion dedicated to a particular feed stream to the reflux reactor may be introduced as a single dose, in stages, or continuously. Similarly, the total amount of organic solvent can be charged in its entirety at the beginning of the first feed step. However, it is common to charge multiple portions of organic solvent over time, particularly with a portion in each feed stream. Conventionally, the solvent portion dedicated to a particular feed stream can be added to the reflux reactor prior to or simultaneously with the start of monomer addition. In certain embodiments of skew-feed polymerization, the reactor contents may be washed with an organic solvent after the addition of the first feed stream. Intermediate wash steps may also be performed between each subsequent feed step. The progress of the polymerization reaction and, if applicable, each feed step thereof, can be monitored by determining the hydroxyl number and acid number by potentiometric titration. When these values ​​reach a predetermined value based on the desired conversion, the reactor contents are typically cooled and then partially or totally neutralized by adding an appropriate amount of base. The reactor contents, containing the hydroxyl-functional (meth)acrylate copolymer polymer (a1), may then be converted into an aqueous dispersion by normal or inverse dilution with water.

[0034] Component (a2) The binder part a) of the two-part (2k) composition of the present disclosure comprises (a2) at least one non-aromatic polyester having active hydrogen groups, the non-aromatic polyester having a number average molecular weight (Mn) of from about 500 to about 5000 Daltons, an acid number of from about 0 to about 30 mg KOH / g, a calculated hydroxyl number of from about 100 to about 600 mg KOH / g, and a calculated hydroxyl functionality of from about 2 to about 8. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. In important embodiments, the non-aromatic polyester (a2) has a number average molecular weight (Mn) of about 500 to about 1500 Daltons, an acid number of about 0 to about 30 mg KOH / g, a calculated hydroxyl number of about 250 to about 400 mg KOH / g, and a calculated hydroxyl functionality of about 4 to about 8. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Typically, the weight ratio of solids of component (a1) hydroxyl-functional (meth)acrylate copolymer to solids of component (a2) polyester is from about 100:1 to about 100:35, e.g., from about 100:5 to about 100:25, from about 100:5 to about 100:20, or from about 100:5 to about 100:15. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Non-aromatic polyesters are typically prepared by polycondensation of at least one hydroxyl-functional component (a2h), at least one carboxyl-functional component (a2c), and, optionally, at least one hydroxycarboxylic acid component (a2hc). The components can be selected in type and amount to achieve the above-described molecular weight, acid number, hydroxyl number, and functionality of the non-aromatic polyester. Generally, the polycondensation reaction can be exemplified by a stoichiometric excess of hydroxyl groups to carboxyl groups. Typically, the stoichiometric excess of hydroxyl groups to carboxyl groups can be 5 to 40 mol%, e.g., 5 to 35 mol%, 5 to 30 mol%, or 5 to 25 mol%. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein.

[0035] The hydroxyl-functional component (a2h) can comprise 75 to 100 weight percent, e.g., 80 to 100 weight percent or 90 to 100 weight percent, of at least one polyol having 3 to 6 hydroxyl groups; and 0 to 25 weight percent, e.g., 0 to 20 weight percent or 0 to 10 weight percent, of at least one diol, based on the weight of the hydroxyl-functional component. In certain embodiments, the hydroxyl-functional component (a2h) can comprise 95 to 100 weight percent, of at least one polyol having 3 to 6 hydroxyl groups; and 0 to 5 weight percent, of at least one diol, based on the weight of the hydroxyl-functional component. In other embodiments, the hydroxyl-functional component (a2h) consists essentially of, or consists of, a polyol having at least 3 to 6 hydroxyl groups. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Suitable polyols having 3 to 6 hydroxyl groups can be saturated or unsaturated, aliphatic or cycloaliphatic; such compounds typically have a molecular weight of 400 daltons or less. Non-limiting examples of aliphatic triols include 1,2,3-propanetriol, 1,2,4-butanetriol, 2-ethyl-2-hydroxymethyl-1,3-propanediol (trimethylolpropane), 3-methyl-1,3,5-pentanetriol, 1,2,3-hexanetriol, 1,2,6-hexanetriol, 2,5-dimethyl-1,2,6-hexanetriol, 1,2,3-heptanetriol, 1,2,3-octanetriol, and 2-hydroxymethyl-1,3-propanediol. Non-limiting examples of aliphatic tetraols and aliphatic pentols include 2,2-bis(hydroxymethyl)propane-1,3-diol (pentaerythritol); pentose; pentopyranose; 6-deoxyhexopyranose; 2,5-anhydrohexitol; 1,5-anhydrohexitol; 6-deoxyhexose; 1-deoxyhexitol; and pentitol. An example of a polyol having six hydroxyl groups is D-glucitol (sorbitol). In embodiments, 2-ethyl-2-hydroxymethyl-1,3-propanediol (trimethylolpropane), 2,2-bis(hydroxymethyl)propane-1,3-diol (pentaerythritol), or a mixture thereof may be used. The present disclosure does not exclude the use of (C2-C4) alkylene oxide adducts of the above diols, triols and higher polyols as reactant polyols having 3 to 6 hydroxyl groups. Diols suitable for use in the hydroxyl-functional component may be saturated or unsaturated, and may be aliphatic or alicyclic dihydroxy compounds. The reactant diols typically have a molecular weight of 250 daltons or less. As used herein, the term "diol" may include its equivalent ester-forming derivatives, but the above molecular weight requirement pertains only to the diol, not its derivatives. Exemplary ester-forming derivatives include acetate esters of diols, as well as, for example, ethylene oxide or ethylene carbonate for ethylene glycol. Typical diols have 2 to 10 carbon atoms. Examples of these diols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 2-methylpropanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, neopentyl glycol, hexanediol, decanediol, hexamethylene glycol, cyclohexanedimethanol, and polyoxyalkylene glycols such as diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, and tetrapropylene glycol. Mixtures of such diols may also be used.

[0036] The carboxyl-functional component (a2c) can comprise 75 to 100%, e.g., 80 to 100% or 90 to 100% by weight of at least one dicarboxylic acid; and 0 to 25%, e.g., 0 to 20% or 0 to 10% by weight of at least one monocarboxylic acid, based on the weight of the carboxyl-functional component. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Suitable dicarboxylic acids for use herein include aliphatic and / or alicyclic dicarboxylic acids. Dicarboxylic acids typically have a molecular weight of less than 600 daltons. The term "dicarboxylic acid," as used herein, includes equivalents of dicarboxylic acids having bifunctional carboxyl groups that function substantially similarly to dicarboxylic acids in reacting with polyols to form polyesters. While such equivalents include esters and ester-forming reactive derivatives, such as acid halides and acid anhydrides, the molecular weight ranges described above relate to the acid, not its equivalent ester or ester-forming derivative. Thus, esters of dicarboxylic acids having a molecular weight greater than 300 daltons, or esters of acids equivalent to dicarboxylic acids having a molecular weight greater than 300 daltons, are included if the acid has a molecular weight less than 300 daltons. Furthermore, dicarboxylic acids may contain any substituent or combination of substituents that does not substantially interfere with the formation and use of the polymers of the present disclosure. Typical dicarboxylic acids include hexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, and alkyl dicarboxylic acids having a total of 2 to 16 carbon atoms. Representative alkyl dicarboxylic acids include glutaric acid, adipic acid, pimelic acid, succinic acid, sebacic acid, azelaic acid, and malonic acid. For example, adipic acid may be used.

[0037] Dimer fatty acids may be used as dicarboxylic acid reactants for the polyester synthesis reactions described above. Exemplary dimer fatty acids include C 18 ~C 22 C, which can be prepared by oxidative coupling of unsaturated monoacids 36 ~C 44Aliphatic diacids include dimer acids obtained from the oxidative coupling of oleic acid, linoleic acid, and tall oil fatty acids. However, in embodiments in which at least one dimer fatty acid is used in the reaction, it is common for at least one non-dimer dicarboxylic acid to be present. More specifically, when at least one dimer fatty acid is used, the dimer fatty acid may be reacted in an amount of 5 to 50% by weight, typically 5 to 40% by weight, 5 to 30% by weight, or 5 to 25% by weight, based on the total weight of the carboxyl-functional components. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Monocarboxylic acids suitable as reactants in polycondensation reactions include aliphatic and / or alicyclic monocarboxylic acids. These monocarboxylic acids typically have a molecular weight of less than 300 daltons. The monocarboxylic acids may be used alone or in combination, and examples include formic acid, acetic acid, propionic acid, n-butanoic acid, isobutanoic acid, 2-ethylhexanoic acid, octanoic acid, isononanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, palmitic acid, and stearic acid.

[0038] The alicyclic / aliphatic hydroxycarboxylic acid component (a2hc) optionally participates in a polycondensation reaction to produce the non-aromatic polyester polyol (a2). When present, the total amount of hydroxycarboxylic acid is typically at most 10% by weight, based on the total weight of the reactant compounds (a2h, a2c, and a2hc). Exemplary hydroxycarboxylic acids include 12-hydroxystearic acid; 6-hydroxyhexanoic acid; citric acid; tartaric acid; and dimethylolpropionic acid. The corresponding lactones may also be used as reactants instead of the monohydroxycarboxylic acids.

[0039] Typically, the reaction mixture provided in the polycondensation reaction is essentially free of solvent. Furthermore, the initial reaction mixture may be essentially free of added water. However, if the reaction is carried out in solution, a suitable solvent can be a non-reactive, essentially anhydrous organic liquid capable of dissolving at least 1% by weight, typically more than 10% by weight, of the polyester product at 25°C. Suitable organic solvents may be used alone or in combination, and examples include aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as heptane and decane; alicyclic hydrocarbons such as cyclohexane and decalin; chlorinated hydrocarbons such as chloroform and trichloroethylene; esters such as ethyl acetate and methyl butyrate; and ethers such as tetrahydrofuran (THF) and dioxane.

[0040] The polycondensation reaction may be carried out in the presence of a suitable catalyst. Common catalysts include acid catalysts and organometallic catalysts, examples of which include titanium, zirconium, and tin alkoxides, carboxylates, and chelates. Typically, the catalyst is a titanium alkoxide, titanium carboxylate, or titanium chelate catalyst. Exemplary titanium alkoxides include tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetrapentyl titanate, tetrahexyl titanate, tetraoctyl titanate, tetranonyl titanate, tetradodecyl titanate, tetrahexadecyl titanate, tetraoctadecyl titanate, tetradecyl titanate, tetraheptyl titanate, and mixtures thereof. The tin or zirconium counterparts of the above alkoxides may be partially substituted as catalysts. Typically, the catalyst is used in an amount of 0.1 to 5 weight percent, e.g., 0.1 to 2.0 weight percent, 0.1 to 1.5 weight percent, or 0.1 to 1.0 weight percent, based on the total weight of the reactants (a2h, a2c, and a2hc). In various non-limiting embodiments, all values ​​and ranges of values, both whole and fractional, inclusive, are expressly contemplated for use herein.

[0041] The polycondensation reaction may be carried out in the presence of at least one stabilizer, which is conventionally present at 0.01 to 5 wt. % based on the total weight of the reactants (a2h, a2c, and a2hc), and which may typically be hydroquinone and its alkylated derivatives; phenolic compounds with electron-withdrawing substituents; and quinoid compounds. Specific examples of such stabilizing compounds, which may be used alone or in combination, include 2,3-dichloro-1,4-naphthoquinone; 2,3-dibromo-1,4-naphthoquinone; 2,3-dicyano-1,4-naphthoquinone; 2-chloro-1,4-naphthoquinone; 2-bromo-1,4-naphthoquinone; 2-nitro-1,4-naphthoquinone; 2,3,6,7,8,9-hexachloro-1,4-naphthoquinone; 3-bromo-2-chloro-1,4-naphthoquinone; 1,4-hydroquinone; 4-tert-butylcatechol; 4-methoxyphenol; methylhydroquinone; 4-chloro-2-nitrophenol; 2,4-dinitropara-cresol; 2,4-dinitrophenol; and phenothiazine. When a stabilizer is used in the polycondensation reaction, one or more known electron donors that form electron donor-acceptor complexes may be further added to the reactant mixture. Such electron donors conventionally comprise a total of 0.01 to 1% by weight, based on the total weight of the reactants (a2h, a2c, and a2hc), and include 1-methylimidazole; 2-methylimidazole; 2-ethyl-4-methylimidazole; 2-heptadecylimidazole; 2-isopropylimidazole; 2-(2-ethyl-4-methylimidazyl)-1-cyanoethane; and 2-undecylimidazole. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein.

[0042] In the synthesis of polyesters, the reactant species, catalyst, and optional stabilizers and electron donors used are typically charged into a suitable reaction vessel equipped with a distillation apparatus. The vessel is typically dried and purged with an inert gas (e.g., nitrogen or argon) prior to charging, maintaining an inert atmosphere within the vessel during the reaction. The vessel temperature is typically set based on the lowest boiling point of the reactants (traditionally an alcohol). In various embodiments, temperatures of about 125 to about 300°C or about 125 to about 275°C may be considered standard. Initially, the vessel may be maintained at atmospheric pressure, but once water distillation is no longer observed, at least a partial vacuum may be applied to the vessel to drive the polycondensation reaction to completion. The reaction may be monitored by analyzing the acid number (Av) of the reactant mixture over time, and the reaction is typically stopped when the measured acid number is less than about 10 mg KOH / g, or ideally less than about 5 mg KOH / g or even less than about 1 mg KOH / g. The time to reach this point will depend on various factors, such as temperature, type of catalyst, and reactants used, but will generally be about 0.5 to about 20 hours, e.g., about 1 to about 8 hours, or about 2 to about 6 hours. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. The polyesters synthesized by the polycondensation reaction can be isolated and purified using methods known in the art, such as filtration, extraction, evaporation, distillation, or chromatography.

[0043] (a3) Further (meth)acrylate copolymers The binder part a) of the composition may, in certain embodiments, further comprise (a3) ​​at least one (meth)acrylate copolymer having active hydrogen groups different from the hydroxyl-functional (meth)acrylate polymer of component (a1), the (meth)acrylate copolymer (a3) ​​having a water solubility of less than about 6 g / 100 mL at about 20° C. The (meth)acrylate component (a3) ​​of this auxiliary or co-binder is typically a minor component of binder part a). For example, (meth)acrylate copolymer (a3) ​​can be present in binder part a) in certain embodiments in an amount of 0 to 20% by weight, based on the weight of said binder part a). In certain embodiments, (meth)acrylate copolymer (a3) ​​can be present in part a) in a partial amount relative to its component (a1), for example, 0 to 20% by weight, 0 to 10% by weight, or 1 to 5% by weight, based on the weight of component (a1). In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. In addition to being water-insoluble, the (meth)acrylate copolymer of component (a3) ​​may not be water-dispersible. For example, the copolymer typically does not form a stable dispersion in water, and the dispersion exhibits settling or phase separation after storage at 40° C. for 4 weeks. The inclusion of such a copolymer tends to increase the hydrophobicity of the aqueous coating composition, which may improve the applicability of the composition and may serve to improve the corrosion resistance and weather resistance of the coating obtained from the composition. In certain embodiments, the (meth)acrylate polymer of component (a3) ​​has a calculated hydroxyl number of about 100 to about 600 mg KOH / g, an acid number of about 0 to about 35 mg KOH / g, and a number average molecular weight of about 1000 to about 4000 Daltons. In other embodiments, the (meth)acrylate polymer of component (a3) ​​has a calculated hydroxyl number of about 100 to about 300 mg KOH / g, e.g., about 100 to about 200 mg KOH / g, an acid number of about 0 to about 30 mg KOH / g, e.g., about 10 to about 30 mg KOH / g, and a number average molecular weight of about 1000 to about 4000 Daltons. In binder part a), cobinder component (a3) ​​may be further exemplified by having a particle size of about 60 to about 200 nm as measured by laser diffraction. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the recited values ​​and therebetween, are expressly contemplated for use herein. The hydroxy-functional (meth)acrylic copolymer (a3) ​​can be commercially available or prepared as described above. The type and amount of the ethylenically unsaturated monomers used in the copolymerization can be selected to achieve the desired molecular weight, acid value, and hydroxyl value of the copolymer. The synthesis of (meth)acrylic copolymer B in the examples of US Patent Application Publication No. 2012237688 (A1) (Huybrechts et al.) can be used herein, and this reference is expressly incorporated by reference in its entirety in various non-limiting embodiments.

[0044] (a4) and (a5) Non-polymeric polyols The addition of certain non-polymeric, low molecular weight polyols to part a) of the composition can improve the moisture resistance of the resulting coating and promote easier mixing between the two parts of the composition, which can lead to improved application of the coating composition and improved appearance of the resulting coating. In one embodiment, binder part a) of the two-component (2K) composition can further comprise (a4) at least one non-polymeric acyclic polyol having a weight average molecular weight (Mw) of less than about 300 Daltons and a water solubility at about 20° C. of less than about 6 g / 100 mL. For example, (a4) the at least one non-polymeric acyclic polyol can be present in binder part a) in an amount of 0 to 10% by weight, based on the weight of binder part a). In certain embodiments, (a4) the at least one non-polymeric acyclic polyol can be present in binder part a) in a small amount relative to its component (a1). For example, binder part a) can comprise 0 to 10%, 0 to 8%, 0 to 5%, or 0 to 3% by weight of (a4) the at least one non-polymeric acyclic polyol, based on the weight of component (a1). In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the recited values ​​and therebetween, are expressly contemplated for use herein. Examples of non-polymeric, acyclic polyols, which may be used alone or in combination, include 2-ethylhexane-1,3-diol; and 2-butyl-2-ethyl-1,3-propanediol.

[0045] In another embodiment (which is not mutually exclusive with the above), the binder part a) of the two-component (2K) composition further comprises (a5) at least one non-polymeric alicyclic polyol having a weight average molecular weight (Mw) of less than about 300 Daltons. For example, the (a5) at least one non-polymeric alicyclic polyol can be present in the binder part a) in an amount of 0 to 10% by weight, based on the weight of the binder part a). In certain embodiments, the (a5) at least one non-polymeric alicyclic polyol can be present in the binder part a) in a small amount relative to its component (a1). For example, the binder part a) can comprise 0 to 10%, 0 to 8%, 0 to 5%, or 0 to 3% by weight of the (a5) at least one non-polymeric alicyclic polyol, based on the weight of component (a1). In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the recited values ​​and therebetween, are expressly contemplated for use herein. Non-polymeric, alicyclic polyols may be used alone or in combination, and examples thereof include 1,4-cyclohexanedimethanol; 1,3-cyclohexanedimethanol; 1,2-cyclohexanedimethanol; 1,4-cyclohexanediethanol; 2,2-bis(4-hydroxycyclohexyl)propane; dianhydro-D-glucitol (isosorbide); and 4,8-bis(hydroxymethyl)tricyclo[5.2.1.0]. 2,6 decane. In one embodiment, the at least one non-polymeric, cycloaliphatic polyol comprises 1,4-cyclohexanedimethanol.

[0046] Part b) Crosslinker The crosslinker part b) of the composition comprises at least one polyisocyanate compound having pendant -NCO groups. The crosslinker part b) of the composition may comprise additional crosslinking compounds in addition to the melamine resin and the polyisocyanate compound having pendant -NCO groups, such as blocked isocyanates. The molar ratio of active hydrogen atoms to -NCO groups in two-component (2K) compositions is from about 5:1 to about 1:5, typically from about 3:1 to about 1:3. The molar ratio of active hydrogen atoms to -NCO groups may be, for example, from about 2:1 to about 1:2 or from about 1.5:1 to about 1:1.5. The term "-NCO groups" includes blocked -NCO groups, which are therefore included in the molar ratio terms. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the values ​​recited above and therebetween, are expressly contemplated for use herein. As used herein, "polyisocyanate" means a compound having at least two -N=C=O functional groups, for example, 2 to 5 or 2 to 4 -N=C=O functional groups. Suitable polyisocyanates include aliphatic, cycloaliphatic, aromatic, and heterocyclic isocyanates, their dimers and trimers, and mixtures thereof. Aliphatic and alicyclic polyisocyanates can contain 6 to 100 carbon atoms, linearly linked or cyclized, and have at least two isocyanate-reactive groups. Examples of suitable aliphatic isocyanates include linear isocyanates such as ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, triisocyanatononane, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, bis(isocyanatoethyl)carbonate, and bis(isocyanatoethyl)ether. Exemplary cycloaliphatic polyisocyanates include dicyclohexylmethane 4,4'-diisocyanate (H12MDI), 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethyl-cyclohexane (isophorone diisocyanate, IPDI), cyclohexane 1,4-diisocyanate, hydrogenated xylylene diisocyanate (H6XDI), 1-methyl-2,4-diisocyanato-cyclohexane, m- or p-tetramethylxylene diisocyanate (m-TMXDI, p-TMXDI), and dimer fatty acid diisocyanate. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein.

[0047] The term "aromatic polyisocyanate" as used herein refers to an organic isocyanate in which an isocyanate group is directly bonded to a ring of a mononuclear or polynuclear aromatic hydrocarbon group. Furthermore, a mononuclear or polynuclear aromatic hydrocarbon group refers to an essentially planar cyclic hydrocarbon moiety of conjugated double bonds, which may be a single ring or may contain multiple fused or covalently bonded rings. The term aromatic also includes alkylaryl. Typically, the hydrocarbon (main) chain contains 5, 6, 7, or 8 main chain atoms per ring. Examples of such planar cyclic hydrocarbon moieties include cyclopentadienyl, phenyl, naphthalenyl,

[10] annulenyl (1,3,5,7,9-cyclodecapentaenyl),

[12] annulenyl, [8]annulenyl, phenalene (perinaphthene), 1,9-dihydropyrene, and chrysene (1,2-benzophenanthrene). Examples of alkylaryl moieties are benzyl, phenethyl, 1-phenylpropyl, 2-phenylpropyl, 3-phenylpropyl, 1-naphthylpropyl, 2-naphthylpropyl, 3-naphthylpropyl and 3-naphthylbutyl. Exemplary aromatic polyisocyanates include all isomers of toluene diisocyanate (TDI), either in isomerically pure form or as a mixture of several isomers; naphthalene 1,5-diisocyanate; diphenylmethane 4,4'-diisocyanate (MDI); diphenylmethane 2,4'-diisocyanate and mixtures of diphenylmethane 4,4'-diisocyanate with the 2,4' isomer or with higher functionality oligomers (so-called crude MDI (e.g., crude MDI); xylylene diisocyanate (XDI); diphenyl-dimethylmethane 4,4'-diisocyanate; di- and tetraalkyl-diphenylmethane diisocyanates; dibenzyl 4,4'-diisocyanate; phenylene 1,3-diisocyanate; phenylene 1,4-diisocyanate; triphenylmethane triisocyanate, 1,3,5-benzene triisocyanate; and 2,4,6-toluene triisocyanate. When used, the polyisocyanates may be biuretized, allophanatized, and isocyanurated by known methods. When used, such derivatives may be substantially free of the parent diisocyanate; the derivatives may be separated from any excess parent diisocyanate by conventional means, including, but not limited to, distillation. The term "polyisocyanate" also includes hydrophilic prepolymers formed by the partial reaction of the aforementioned aliphatic, cycloaliphatic, aromatic, and heterocyclic isocyanates with polyether or polyester polyols to give isocyanate-functional oligomers, which may be used alone or in combination with free isocyanates. The term "polyisocyanate" further includes ionically modified isocyanate-functional compounds, such as ionically modified isocyanate-functional prepolymers. Ionically modified polyisocyanates contain at least two isocyanate groups and at least one ionic or ionogenic group. In certain embodiments, an anionically modified isocyanate-functional compound, such as an anionically modified isocyanate-functional prepolymer, may be included in the crosslinker part b). In this regard, suitable anionic or anionogenic groups include carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, and salts thereof. Suitable salts that can neutralize the anionic groups to form such salts include alkali metals, such as Na and K; ammonium; and trialkylamines, such as triethylamine and triisopropylamine. Exemplary polyisocyanates commercially available from Covestro AG and that may be used in the present disclosure include Desmodur® N3900; Bayhydur® Ultra 2487 / 1; Bayhydur® Ultra 2700; Bayhydur® Ultra 3100; Bayhydur® Ultra 304; Bayhydur® Ultra 305; Bayhydur® Ultra 307; Bayhydur® XP 2451 / 1; Bayhydur® XP 2547; Bayhydur® XP 2655; Bayhydur® XP 2759; Bayhydur® 2858 XP; Bayhydur® Eco 701-90; Bayhydur® 401-60 PGDA; and Bayhydur® 401-70 MPA / X.

[0048] Additives and auxiliary ingredients The compositions of the present disclosure may or may not further comprise one or more adjuvants and additives that can impart improved properties to the compositions and coatings obtained therefrom. For example, the adjuvants and additives may impart one or more of the following: reduced dullness; improved clarity of image (DOI); extended effective processing time; shorter cure time; reduced residual tack; and improved leveling. Such adjuvants and additives include catalysts; plasticizers; stabilizers, such as UV stabilizers; reactive diluents; drying or moisture scavengers; adhesion promoters; wetting agents; defoamers; flame retardants; rheology control agents; color pigments; dyes; effect pigments; cosolvents; and non-reactive diluents. Such adjuvants and additives can be used in any desired combination and proportions as long as they do not adversely affect the properties and essential characteristics of the composition. Although there may be exceptions in certain cases, these adjuvants and additives typically constitute 0 to 40% by weight, e.g., 0 to 30% by weight, of the total composition. Generally, reactive group-containing auxiliary materials and additives can be incorporated into the appropriate part of the two-part (2K) composition to ensure its storage stability. Non-reactive materials can be incorporated into either or both of the two parts. For example, the crosslinker part b) of the composition may, in certain embodiments, be free of compounds containing active hydrogen atoms.

[0049] The composition may contain one or more catalysts for the reaction of -NCO groups with active hydrogen compounds. Standard catalysts known in the art include stannous salts of carboxylic acids, such as stannous octoate, stannous oleate, stannous acetate, and stannous laurate; dialkyltin dicarboxylates, such as dibutyltin dilaurate and dibutyltin diacetate; tertiary amines; alkanolamine compounds; 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine; tetraalkylammonium hydroxides; alkali metal hydroxides; alkali metal alcoholates; tin alkoxides, such as dibutyltin dimethoxide, dibutyltin diphenoxide, and dibutyltin diisoproxide; tin oxides, such as dibutyltin oxide and dioctyltin oxide; reaction products of dibutyltin oxide with phthalic acid esters; tin mercaptides; alkyl titanates; organoaluminum compounds, such as aluminum trisacetylacetonate, aluminum tris(acetylacetonate), and aluminum thiazolinone. tris-ethyl acetoacetate and diisopropoxyaluminum ethyl acetoacetate; chelating compounds such as zirconium tetraacetylacetonate and titanium tetraacetylacetonate; organosilicon titanium compounds; bismuth tris-2-ethylhexanoate; acid compounds such as phosphoric acid and p-toluenesulfonic acid; triphenylborane; triphenylphosphine; 1,8-diazabicycloundec-7-ene (DB U); 1,5-diazabicyclo[4.3.0]non-5-ene; 1,4-diazabicyclo[2.2.2]octane; 4-dimethylaminopyridine; 1,5,7-triazabicyclo[4.4.0]dec-5-ene; 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene; 1,8-bis(tetramethylguanidino)naphthalene; and 2-tert-butyl-1,1,3,3-tetramethylguanidine. Depending on the nature of the isocyanate, the amount of catalyst used is typically 0.005 to 2 weight percent of the composition. For example, the composition may include 0.01 to 2 weight percent or 0.01 to 1 weight percent of catalyst, based on the total weight of the composition. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein.

[0050] The addition of certain additives can promote adhesion of the coating composition to certain substrates. In this regard, the composition may comprise 0 to 5% by weight, for example 0.5 to 5% by weight, based on the total weight of the composition, of at least one additive selected from: morin (2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-coumarone-4-ketone); 3,7-dihydroxy-2-naphthoic acid (3,7-dihydroxynaphthlene-2-carboxylic acid); pyrogallolcarboxylic acid (2,3,4-trihydroxybenzoic acid); 3,4-dihydroxy-benzeneguanidine-acetic acid; gallic acid (3,4,5-trihydroxybenzoic acid); para-aminosalicylic acid (4-amino-2-hydroxybenzoic acid, PAS); flutter acid (4,4'-methylene-bis(3-hydroxy-2-naphthoic acid)); citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid); and mixtures thereof. In certain embodiments, citric acid, gallic acid, or para-aminosalicylic acid (PAS) may be used alone or in combination.

[0051] The term "pigment," as used herein, refers to a molecule that is insoluble in a liquid carrier and that imparts either color or an optical effect. In certain embodiments, the composition may include at least one color pigment. The color pigments useful herein may be organic or inorganic. The color pigments may be used alone or in combination, and examples thereof include azo pigments; anthraquinone pigments; benzimidazolone pigments; isoindoline pigments; naphthol pigments, such as naphthol red; nitroso pigments; perinone pigments; perylene pigments; polycyclic pigments; pyrrolopyrrole pigments; phthalocyanines, such as copper phthalocyanine blue and copper phthalocyanine green; quinacridones, such as quinacridone violet; quinophthalone pigments; dioxazine pigments; carbon black; and anazuline. antimony oxide; barium metaborate; barium sulfate; cadmium sulfide; cadmium selenide; calcium carbonate; calcium metaborate; calcium metasilicate; chromium oxide; clay; copper oxide; copper oxychloride; feldspar; iron oxides, such as yellow iron oxide and red iron oxide; kaolinite; lithopone; magnesium silicate; nepheline syenite; silicates; sulfides; talc; titanium dioxide; ultramarine; zinc chromate; zinc oxide; and zinc phosphate. In certain embodiments, the composition may include at least one effect pigment (meaning a pigment that exhibits an optical effect not caused by absorption). Specific examples include graphite effect pigments, metal effect pigments, and pearlescent pigments. The effect pigment may have at least one of the following: a specific surface area of ​​about 1 to about 60 m2, as measured using nitrogen absorption by the Brunauer-Emmett-Teller (BET) method; 2 / g, for example, about 5 to about 50 m 2 / g; and an average volume particle size (Dv50) as measured by laser diffraction of about 1 to about 500 μm, e.g., about 5 to about 100 μm. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of and between the recited values, are expressly contemplated for use herein.

[0052] Metallic effect pigments may comprise needle-shaped, spherical, ellipsoidal, cylindrical, bead-like, cubic, platelet-like or flake-shaped particles. Particles of different shapes may be used alone or in combination. Examples of metals that can comprise metallic effect pigments include aluminum, copper, copper-zinc alloys, copper-tin alloys, stainless steel, carbon steel, iron, silver, zinc, nickel, titanium, chromium, manganese, vanadium, magnesium, and zinc-magnesium alloys. The component metals may be coated with one or more inert oxides to form the effect pigment. Exemplary metal oxides include silicon dioxide, titanium dioxide, zinc oxide, zirconium dioxide, tin oxide, cerium dioxide, vanadium oxide, manganese oxide, lead oxide, chromium oxide, iron oxide, aluminum oxide, and tungsten oxide. When present in a pigment, the thickness of such a metal oxide layer will typically be 20 to 400 nm, e.g., 50 to 400 nm or 50 to 250 nm. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. The pearlescent pigment comprises a transparent, non-metallic, platelet-shaped substrate coated with at least one layer comprising a metal oxide having a refractive index. In some embodiments, multiple layers of metal oxide are used, with the refractive index of successive layers differing by at least about 0.1. In some embodiments, the pearlescent pigment has an interference color when viewed against a black background. Exemplary non-metallic platelet substrates include natural mica; synthetic mica; bismuth oxychloride; graphite; aluminum oxide; mica-like iron oxide; perlite; silicon dioxide; borosilicate glass; glass; titanium dioxide-coated mica; and iron oxide-coated mica. Exemplary metal oxides from which one or more coating layers of the pearlescent pigment are formed include silicon dioxide, titanium dioxide, zinc oxide, zirconium dioxide, tin oxide, cerium dioxide, vanadium oxide, manganese oxide, lead oxide, chromium oxide, iron oxide, aluminum oxide, and tungsten oxide. The thickness of each metal oxide layer of the pearlescent pigment may be determined independently, but is conventionally about 20 to about 400 nm, e.g., 50 to 400 nm or 50 to 250 nm. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the values ​​recited and therebetween, are expressly contemplated for use herein.

[0053] Rheology control agents are optionally useful in the present compositions and can include fillers, thickeners, and combinations thereof. The amount of rheology control agent in the composition typically does not exceed 10% by weight, based on the weight of the composition. The composition can include, for example, 0-8%, 0-5%, or 0-2% by weight of rheology control agent, based on the weight of the composition. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Exemplary thickeners include clay-based thickeners such as organoclays; polysaccharides such as guar and xanthan; polyacrylates; and associative thickeners. Cellulose or cellulose derivatives that can be used as polysaccharide thickeners include, in particular, carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, cellulose nanofibers, and cellulose nanocrystals. The filler may comprise acicular, spherical, ellipsoidal, cylindrical, bead-like, cubic, platelet-like, or flaky particles, which may be used alone or in combination. It is further contemplated that aggregates of two or more particle types may be used. The filler typically has a mean particle size by volume (Dv50) of about 0.1 to 1500 μm, e.g., about 1 to 1250 μm, as measured by laser diffraction. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Exemplary fillers include calcium carbonate, calcium oxide, calcium hydroxide (lime powder), precipitated and / or pyrogenic silica, zeolite, bentonite, wollastonite, magnesium carbonate, diatomaceous earth, barium sulfate, alumina, clay, talc, titanium dioxide, iron oxide, zinc oxide, sand, quartz, flint, mica, glass beads, glass powder, and other ground mineral substances. Organic fillers, particularly wood fiber, wood flour, sawdust, cellulose, cotton, pulp, cotton, wood chips, shredded straw, rice husks, crushed walnut shells, and other shredded fibers, can also be used. Short fibers, such as glass fiber, glass filament, polyacrylonitrile, carbon fiber, Kevlar® fiber, or polyethylene fiber, can also be added.

[0054] When present, the pyrogenic and / or precipitated silica has a BET specific surface area of ​​about 10 to about 90 m 2 / g. Such silica, when used, may not cause an increase in the viscosity of the composition, but may contribute to strengthening the cured composition. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the values ​​recited and therebetween, are expressly contemplated for use herein. Similarly, the BET specific surface area is higher, advantageously from about 100 to about 250 m 2 / g of pyrogenic and precipitated silica is envisioned for use as fillers; the high BET surface area allows the strengthening effect of the cured composition to be achieved with a lower mass fraction of silica. In various non-limiting embodiments, all values ​​and ranges of values, both whole and fractional, inclusive, are expressly contemplated for use herein. Hollow spheres with mineral or plastic shells can also be used. The hollow spheres can be, for example, hollow glass spheres commercially available under the trade name Glass Bubbles®. Plastic-based hollow spheres, such as Expancel® or Dualite®, can also be used. For example, the hollow spheres can contain inorganic or organic materials, each having an average volume diameter (Dv50) of 1 mm or less, typically 500 μm or less, as measured by laser diffraction.

[0055] Fillers that impart thixotropic properties to compositions are common in many applications. Such fillers, also known as rheology aids, include, for example, hydrogenated castor oil, fatty acid amides, and swellable plastics such as PVC. For purposes of this disclosure, a "plasticizer" is a substance that reduces the viscosity of the composition, thereby facilitating its processability. As used herein, the plasticizer may comprise up to 10% by weight, or up to 5% by weight, based on the total weight of the composition, and is typically selected from the following: diurethanes; ethers of monofunctional linear or branched C4-C16 alcohols, such as Cetiol OE (available from BASF); esters of abietic acid, butyric acid, thiobutyric acid, acetic acid, propionic acid, and citric acid; esters based on nitrocellulose and polyvinyl acetate; fatty acid esters; dicarboxylic acid esters; esters of OH-group-bearing or epoxidized fatty acids; glycolic acid esters; benzoic acid esters; phosphate esters; sulfonic acid esters; trimellitic acid esters; polyether plasticizers, such as end-capped polyethylene or polypropylene glycol; polystyrene; hydrocarbon plasticizers; chlorinated paraffins; and mixtures thereof. While phthalate esters could, in principle, be used as plasticizers, it should be noted that phthalate esters are uncommon due to their potential toxicity.

[0056] For the purposes of this disclosure, "stabilizer" should be understood as an antioxidant, a heat stabilizer, or a hydrolysis stabilizer. Herein, the stabilizers may constitute a total of up to 10% by weight, or up to 5% by weight, based on the total weight of the composition. Standard commercially available examples of stabilizers suitable for use herein include sterically hindered phenols; thioethers; benzotriazoles; benzophenones; benzoates; cyanoacrylates; acrylates; amines of the hindered amine light stabilizer (HALS) type; phosphorus; sulfur; and mixtures thereof. To further extend shelf life, it is often recommended to use a desiccant to further stabilize the composition of the present disclosure against moisture penetration. Examples of suitable desiccants or moisture scavengers include silica gel; anhydrous calcium sulfate (anhydrite); calcium sulfate dihydrate (gypsum); calcium oxide; montmorillonite clay; molecular sieves, including natural or synthetic zeolites; and activated alumina.

[0057] Waxes useful in the present disclosure can have a softening point of about 50 to about 150°C and can include one or more of the following: polyethylenes having a number average molecular weight (Mn) of about 500 to about 7500; petroleum waxes, such as paraffin wax and microcrystalline wax; synthetic waxes made by polymerizing carbon monoxide and hydrogen, such as Fischer-Tropsch wax; polyolefin waxes, including functionalized polyolefin waxes, examples of which include maleated polyethylene, maleated polypropylene, and poly(ethylene-co-propylene) maleate; and hydrogenated animal, fish, or vegetable oils. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the values ​​recited above and therebetween, are expressly contemplated for use herein.

[0058] Reactive diluents may be used to reduce the viscosity of compositions according to the present disclosure for certain applications. The total amount of reactive diluents present is typically 0 to 10 wt. %, e.g., 0 to 5 wt. %, based on the total weight of the composition. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. The presence of co-solvents and non-reactive diluents in the compositions of the present disclosure is not precluded if they can effectively reduce the viscosity thereof. For example, and by way of example only, the composition may contain one or more of the following: alkyl acetate solvents, such as ethyl acetate, n-propyl acetate, butyl acetate, n-butyl acetate, propylene glycol monomethyl ether acetate, and methoxypropyl acetate (MPA); alkyl propionate solvents, such as n-butyl propionate and n-pentyl propionate; dibasic acid esters, such as dimethyl succinate, dimethyl glutarate, and dimethyl adipate; (di)alkyl carbonate solvents, such as ethylene carbonate, propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC); ethers, such as tetrahydrofuran, dioxane, and dimethoxyethane; glycol ether solvents, such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol diphenyl ether, diethylene glycol, diethylene glycol monomethyl ether, and diethylene glycol monomethyl ether. diethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-butyryl ether, propylene glycol butyl ether, propylene glycol phenyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether and dipropylene glycol di-n-butyl ether; the amide solvents dimethylacetamide and N-methylpyrrolidone; ketone solvents such as acetone, diisobutyl ketone, isobutylheptyl ketone, isophorone, methyl ethyl ketone, methyl n-amyl ketone and methyl isobutyl ketone; toluene; xylene; diphenylmethane; diisopropyl naphthalene; petroleum fractions such as Solvesso® products (available from Exxon); and chlorohydrocarbon solvents such as 4-chlorotrifluoromethylbenzene and 3,4-bis(dichloro)trifluoromethylbenzene. Any co-solvent or non-reactive diluent of a two-part (2K) composition need not be added separately to one or more components or to the composition itself. Alternatively, one or more components of the composition may be provided in a co-solvent or diluent. Any solvent or diluent included in the crosslinker part b) of the composition may not contain active hydrogen atoms in certain embodiments. Typically, the cosolvent and non-reactive diluent together constitute less than 5% by weight, particularly less than 1% by weight, based on the total weight of the composition.By at least partially eliminating the cosolvent and non-reactive diluent, the two-component (2K) aqueous composition can have a volatile organic compound (VOC) content of at most about 420 g / L, for example at most about 360 g / L, for example at most about 300 g / L, or at most about 240 g / L, as measured according to ISO 11890-2:2006.In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, including those between and including the above values, are expressly contemplated for use herein.

[0059] Method and Application In two-component (2K) curable compositions, the reactive components are combined and mixed in a manner that induces their curing. The reactive components are mixed under sufficient shear to obtain a homogeneous mixture. This can be achieved without the need for special conditions or special equipment. Nevertheless, suitable mixing devices include static mixers; magnetic stirrers; wire whisks; augers; batch mixers; planetary mixers; CW Brabender or Banburry® style mixers; and high-shear mixers, such as blade blenders and rotary impellers. In certain embodiments, after the reactive components are mixed, one or more of water, cosolvents, and reactive diluents may be added under mixing to adjust the viscosity of the composition. For small-scale applications, typically involving volumes of less than 2 liters, a typical package for two-component (2K) compositions is a parallel double cartridge or a coaxial cartridge. This contains two tubular chambers arranged side by side or inside each other and sealed with pistons. The pistons actuate the parts, advantageously via a closely mounted static or dynamic mixer, to extrude them from the cartridge. For larger-volume applications, the two parts of the composition can be advantageously stored in drums or buckets. In this case, the two parts are extruded through a hydraulic press, particularly via a follower plate, and then delivered via a pipeline to a mixing device that ensures a highly homogeneous mixing of the hardener and binder parts. The binder part is typically sealed with an airtight and moisture-proof seal, allowing both parts to be stored for long periods, ideally for 12 months or more.

[0060] Non-limiting examples of two-component dispensing devices and methods that may be suitable for the present disclosure include those described in U.S. Pat. Nos. 6,129,244 and 8,313,006, each of which is expressly incorporated by reference in its entirety in various non-limiting embodiments. More typically, the composition is applied to the required surface and then cured in place. Before applying the composition, it is often recommended to pretreat the relevant surface to remove foreign matter from the surface. This step can, if applicable, promote the subsequent adhesion of the composition to the surface. Such treatments are known in the art and can be carried out in one or multiple steps. In some embodiments, adhesion of the coating composition to the optionally pretreated substrate surface can be promoted by applying a primer to the surface, which may be necessary to ensure effective anchoring and / or cure time of the adhesive composition on the inert substrate. As described below with respect to multi-layer coatings, the inclusion of a further intermediate layer between the primer and the coating composition of the present disclosure is not precluded.

[0061] Typically, the composition is applied to the required surface of the substrate by conventional application methods such as brushing; roll coating; doctor blade application; printing methods; and spraying methods, including, but not limited to, air atomized spraying, air assisted spraying, airless spraying, and high volume low pressure spraying. The composition is applied to a surface at a wet film thickness of about 10 to about 500 μm. Applying thinner layers within this range is more economical and reduces the likelihood of harmful thick cured areas. However, application of thinner coatings or layers must be controlled to avoid the formation of discontinuous cured films. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. Curing of the applied composition occurs at temperatures ranging from about 20 to about 200°C, typically from about 20 to about 160°C. Suitable temperatures depend on the specific compounds present and the desired cure rate and can be determined in each case by one skilled in the art, using simple preliminary testing, if necessary. For example, in vehicle assembly line applications, cure temperatures of about 80 to about 160°C or about 100 to about 140°C may be effective. Conversely, in refinish applications, cure temperatures of about 20 to about 80°C or about 40 to about 60°C may be effective. For applications to large vehicles and transportation vehicles (e.g., trucks, buses, and railcars), cure temperatures of about 20 to about 80°C may be used. Naturally, curing at lower temperatures within the above ranges is advantageous because it avoids the need to heat or cool the mixture significantly from typically prevailing ambient temperatures. However, where applicable, the temperature of the mixture formed from the individual components of the composition may be elevated above the mixing and / or application temperatures using conventional means, such as baking and microwave induction. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive of the recited values ​​and therebetween, are expressly contemplated for use herein. The present disclosure also provides an article comprising a metallic substrate and a multi-layer coating disposed on the metallic substrate, wherein at least one layer of the multi-layer coating comprises the cured product described herein. While the use of the cured composition as an undercoat (such as a primer or sealer) within the multi-layer coating is not precluded, the cured coating composition is more suitable for use in or as a solid color basecoat, solid color topcoat, and / or clearcoat. For example, the cured coating composition can be used in or as a transparent clearcoat.

[0062] An exemplary article is illustrated in accompanying Figure 1. The illustrated article (1) comprises a metallic substrate (10), a multi-layer coating (11) disposed on the metallic substrate, the multi-layer coating (11) comprising a primer layer (110) disposed on the metallic substrate, a basecoat layer (120) comprising a compound that imparts color and / or visual effect, the basecoat layer being disposed on the primer layer (110), and a clearcoat layer (130) comprising the cured product of the two-part (2K) composition described above and disposed on the basecoat layer (120). The primer layer (110) is typically applied to promote adhesion between the substrate surface and subsequent coating layers. Additionally, the primer coating layer may serve to enhance the physical properties of the overall coating system, particularly corrosion resistance and impact strength. Furthermore, the primer coating layer may contribute to the overall appearance of the coating system by providing a smooth layer onto which subsequent layers may be applied. The primer layer (110) is depicted in FIG. 1 as being disposed directly on and in contact with the metallic substrate (10). However, it will be understood that one or more intermediate coating layers may be disposed between the metallic substrate and the primer layer (110). A conversion coating layer is a representative example of such an intermediate coating layer. As used herein, the term "conversion" refers to a surface treatment that causes the chemical conversion of a surface material to a different material. Typically, a metal or alloy surface substrate is chemically treated to provide a highly adherent conversion coating, which consists, in whole or in part, of the substrate metal in a stabilized form (e.g., an oxidized form). In addition to exhibiting high corrosion resistance, such a conversion coating can provide a strong bonding affinity for a subsequent primer layer (110). A single primer layer (110) is depicted in FIG. 1 for illustrative purposes only. However, in certain embodiments, multiple primer layers (110) may be present. Regardless of whether the primer is applied in a single layer or multiple layers, the total thickness of the at least one primer layer can typically be from about 10 to about 200 microns, e.g., from about 10 to about 150 microns, from about 10 to about 75 microns, or from about 20 to about 75 microns. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. The basecoat layer (120) in Figure 1 contains compounds that impart color and / or visual effects and is disposed on the primer layer (110). If the primer is applied in multiple layers, the basecoat layer is disposed on the topmost primer layer against the surface of the metallic substrate (10). A single base coat layer (120) is depicted in FIG. 1 for illustrative purposes only. However, in certain embodiments, multiple base coat layers (120) may be present. The lowest of these base coat layers may be disposed directly on and in contact with the primer layer (110). Regardless of whether the base coat is applied in a single layer or multiple layers, the total thickness of the at least one base coat layer may typically be from about 5 to about 100 microns, e.g., from about 5 to about 50 microns, from about 5 to about 40 microns, or from about 5 to about 30 microns. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. In Figure 1, a clear coat layer (130) comprises the cured product of the two-component (2K) composition and is disposed on the base coat layer (120). If the base coat is applied in multiple layers, the clear coat layer (130) is disposed on the topmost base coat layer against the surface of the metallic substrate (10). The clear coat layer (130) typically has good chemical resistance, mechanical abrasion resistance, and weather resistance. Furthermore, the clear coat layer (130) will have sufficient optical properties, including transparency and gloss. Again, a single clear coat layer (130) is depicted in FIG. 1 for illustrative purposes only. However, in certain embodiments, multiple clear coat layers (130) may be present. The lowest of these clear coat layers may be disposed directly on and in contact with the base coat layer (120). Regardless of whether the clear coat is applied in a single layer or multiple layers, the total thickness of the at least one clear coat layer may typically be from about 10 to about 500 microns, e.g., from about 10 to about 200 microns, from about 20 to about 100 microns, or from about 30 to about 90 microns. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. The or each clear coat layer (130) of the article may, in certain embodiments, be substantially transparent to at least visible light. Thus, for example, the or each clear coat layer may have a transmittance (T) according to ASTM D1746 (2023).R ) measurement.

[0063] A further exemplary article is illustrated in accompanying Figure 2. The illustrated article (1) comprises a metallic substrate (20), a multi-layer coating (21) disposed on the metallic substrate, the multi-layer coating (21) comprising a primer layer (210) disposed on the metallic substrate, a basecoat layer (220) comprising a compound that imparts color and / or visual effect, the basecoat layer being disposed on the primer layer (210), a tie layer (225) disposed on the basecoat layer (220), and a clearcoat layer (230) comprising the cured product of the two-part (2K) composition described above and disposed on the tie layer (225). The tie layer (225) can be inserted between the base coat layer (220) and the clear coat layer (230) to enhance the adhesion between these layers. This insertion typically allows the tie layer (225) to be substantially transparent to visible light. Thus, for example, the tie layer (225) can have a transmittance (T) according to ASTM D1746 (2023). R ) measurement, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein. A single tie layer (225) is depicted in FIG. 2 for illustrative purposes only. However, in certain embodiments, multiple tie layers (225) may be present. In these embodiments, the bottommost of these tie layers may be disposed directly on the base coat layer (220); a clear coat layer (230) comprising the cured product of the two-component (2K) composition is disposed directly on top of the tie layer (225). The total thickness of the at least one tie layer may, in embodiments, be less than the total thickness of the clear coat layer (230). Alternatively, or additionally, the total thickness of the at least one tie layer may be from about 1 to about 50 microns, e.g., from about 1 to about 25 microns, from about 5 to about 25 microns, or from about 5 to about 20 microns. In various non-limiting embodiments, all values ​​and ranges of values, both integers and fractions, inclusive, are expressly contemplated for use herein.

[0064] A method for forming a multilayer coating conventionally incorporates the steps of: i) providing a metallic substrate; ii) applying a first layer of a first curable coating composition directly onto the metallic substrate; iii) at least partially curing the first layer; iv) applying a second layer of a second curable coating composition directly onto the at least partially cured first layer; v) at least partially curing the second layer; vi) applying a third layer of a third curable coating composition directly onto the at least partially cured second layer; and vii) at least partially curing the third layer. Steps vi) and vii) may be performed in an iterative process, and repeated to deposit four or more layers onto the metallic substrate. Considering the multilayer coating shown in Figures 1 and 2, the first, second, third, and further curable compositions, as described above, provide at least one primer layer; at least one basecoat layer; optionally at least one tie layer; and at least one clearcoat layer. The metallic substrate provided in step i) may typically be pretreated prior to step ii), such pretreatment may include at least one of cleaning the surface of the metal substrate, polishing the surface of the metal substrate, applying an anti-corrosion coating to the metal substrate, or applying a conversion coating to the metal substrate as described above. Cleaning serves to remove foreign matter from the surface of metallic substrates. Cleaning treatments are known in the art and can be carried out in a single or multi-step manner, for example, by using one or more of the following: etching with an acid and optionally an oxidizing agent appropriate for the substrate; ultrasonic treatment; plasma treatment (such as chemical plasma treatment, corona treatment, atmospheric plasma treatment, and flame plasma treatment); immersion in an aqueous alkaline degreasing bath; treatment with an aqueous cleaning emulsion; treatment with a cleaning solvent, such as carbon tetrachloride or trichloroethylene; and water rinsing, preferably with deionized or demineralized water. When an aqueous alkaline degreasing bath is used, it is usually desirable to remove any remaining degreaser on the surface by rinsing the substrate surface with deionized or demineralized water.

[0065] Regardless of cleaning the substrate, the surface of the metallic substrate (10) may be polished. Polishing typically involves sanding, which may be performed, for example, using an orbital sander with sandpaper of a predetermined grit. After surface polishing, the metallic substrate may optionally be cleaned to remove dust or other adhering dirt or contaminants generated during the polishing operation. As used in the above methods, the term "at least partially cured" means that curing of the curable coating composition has been initiated, e.g., crosslinking of the components of the composition has been initiated. This term includes any amount of curing by application of curing conditions, from the formation of a single crosslinked state to a fully crosslinked state. The rate and mechanism by which the coating composition cures depends on various factors, such as the components of the composition, the functional groups of the components, and the parameters of the curing conditions. At least partial solidification of a given coating layer generally indicates curing or drying, however, both drying and curing may be manifested in other ways, such as a change in viscosity of the coating layer, an increase in temperature of the coating layer, and / or a change in transparency / opacity of the coating layer. Steps iv) and vi) of the above coating method are typically initiated only when the at least partially cured or partially dried preceding layer is capable of substantially retaining its shape when exposed to ambient conditions. By "substantially retaining its shape," we mean that at least about 50% by volume, more typically at least about 80% by volume or about 90% by volume, of the at least partially cured or dried layer retains its shape and does not flow or deform when exposed to ambient conditions for 5 minutes. Under these circumstances, gravity typically does not significantly affect the shape of the at least partially cured or partially dried layer when exposed to ambient conditions. The shape of the at least partially dried or at least partially cured layer can typically affect whether the layer substantially retains its shape. For example, if the layer is rectangular or another simple shape, the at least partially cured or dried layer may be more resistant to deformation, even at lower levels of curing or drying, than a layer with a more complex shape. In certain embodiments, the application of each subsequent layer (step iv; step vi) occurs before the at least partially cured layer reaches its final cured state, while the layer is still "green." In such embodiments, the application of layers can be considered "wet-on-wet," meaning that adjacent layers are at least physically bonded to each other and may also chemically bond to each other. For example, it is possible for the components of the first and subsequent layers to chemically crosslink / cure beyond the application line, an effect that can be beneficial to the life, durability, and appearance of the finished article. The difference between a partially cured and a final cured state is whether the partially cured layer can undergo further curing or crosslinking. This does not, in fact, exclude the possibility that functional groups present in the final cured state may remain unreacted due to steric hindrance or other factors. In the iterative process described above, the thickness, width, shape, and continuity of each layer may be independently selected such that the thickness, width, shape, and continuity of each layer may be the same or different from one another with respect to one or more of these. For example, a given subsequent layer may contact only a portion of the exposed surface of a preceding layer that has at least partially cured or dried, and depending on the desired shape of the coating layer, the subsequent layer may be selectively built up on that layer. The following examples are illustrative of the present disclosure and are not intended to limit the scope of the disclosure. [Example]

[0066] In the examples below, the following commercially available products are used: CE10P: Cardura E10P; versatic acid glycidyl ester, available from Hexion. BYK® 345: Silicone surfactant, available from Altana. BYK® 333: A silicone-containing surface additive, available from Altana. Tinuvin® 292: Hindered amine light stabilizer, available from BASF. Tinuvin® 1130: A UV absorber of the hydroxyphenylbenzotriazole class, available from BASF. EmpolS: fatty acid dimer, available from Henkel Corporation. Bayhydur XP2655: Hydrophilic aliphatic polyisocyanate based on hexamethylene diisocyanate (HDI), available from Covestro AG. Desmodur® N 3900: Hexamethylene diisocyanate trimer, available from Covestro AG. Unless otherwise noted, all remaining compounds are available from Sigma Aldrich.

[0067] RSE1: Reference Synthesis Example 1 A reactor equipped with a propeller agitator, thermometer, condenser, and monomer / initiator feed system was charged with 385 g of CE10P and 75 g of ethoxypropanol and heated to approximately 150° C. A mixture of 103 g of hydroxyethyl methacrylate, 507 g of styrene, 136 g of acrylic acid, 18 g of dicumyl peroxide, 77 g of CE10P, and 88 g of ethoxypropanol was added to the reactor over 2.5 hours while the contents were maintained at 150° C. After the feeds, the contents of the reactor were held for 30 minutes. After this hold period, 175 g of hydroxyethyl methacrylate, 49 g of acrylic acid, 230 g of isobutyl methacrylate (IBMA), 7.3 g of dicumyl peroxide, and 102 g of ethoxypropanol were added to the reactor over 2.5 hours while the contents were held at 150° C. This addition was followed by a rinse step of the feed system with 58 g of ethoxypropanol. After the rinse step, the contents of the reactor were held at 150° C. for 2 hours. The reactor contents were cooled to 100° C. and 177 g of ethoxypropanol was distilled off. 54 g of dimethylaminoethanol (DMEA) was added to the contents, and the resulting polymer blend was then diluted with 1850 g of water preheated to about 70° C. The properties measured for the resulting dispersion were as follows: solids content 45.1% by weight; viscosity 4500 centipoise; acid number 27.8 mg KOH / g; and pH 8.0. Visual stability assessment showed that the resulting aqueous dispersion did not settle out when stored at 60° C. for 4 weeks. The molecular weight of the synthesized copolymer was determined by gel permeation chromatography (GPC) using polystyrene calibration standards according to ASTM 3536 to be: number average molecular weight (Mn) 5300 Daltons; and weight average molecular weight (Mw) 32800 Daltons.

[0068] RSE2: Reference Synthesis Example 2 A dispersion of a low molar mass hydroxyl-functional (meth)acrylate copolymer was prepared according to the process of Reference Synthesis Example 1 (RSE1) by increasing the initiator dosage in both stages by 50 wt % and using the same dosages of the other materials. The molecular weight of the synthesized copolymer was determined by gel permeation chromatography (GPC) using polystyrene calibration standards according to ASTM 3536 to be: number average molecular weight (Mn) 4200 Daltons; and weight average molecular weight (Mw) 17556 Daltons. In a visual assessment of stability, the resulting aqueous dispersion exhibited sedimentation in less than 4 weeks when stored at 60° C. Due to insufficient stability, further evaluation of this synthetic copolymer was not pursued.

[0069] SE1: Synthesis Example 1 A reactor equipped with a propeller agitator, thermometer, condenser, and monomer / initiator feed system was charged with 385 g of CE10P and 75 g of ethoxypropanol and heated to approximately 150° C. A mixture of 103 g of hydroxyethyl methacrylate, 217 g of styrene, 136 g of acrylic acid, 250 g of isobornyl methacrylate, 18 g of dicumyl peroxide, 77 g of CE10P, and 88 g of ethoxypropanol was added to the reactor over 2.5 hours while the contents were maintained at 150° C. After the feeds, the contents of the reactor were held for 30 minutes. After this hold period, 170 g of hydroxyethyl methacrylate, 47.5 g of acrylic acid, 222 g of isobutyl methacrylate (IBMA), 7.3 g of dicumyl peroxide, and 102 g of ethoxypropanol were added to the reactor over 2.5 hours while the contents were held at 150° C. This addition was followed by a rinse step of the feed system with 58 g of ethoxypropanol. After the rinse step, the contents of the reactor were held at 150° C. for 2 hours. The reactor contents were cooled to 100° C. and 190 g of ethoxypropanol was distilled off. 52 g of dimethylaminoethanol (DMEA) was added to the contents, and the resulting polymer blend was then diluted with 1850 g of water preheated to about 70° C. The properties measured for the resulting dispersion were as follows: solids content 45.1% by weight, viscosity 3800 centipoise, acid number 27.8 mg KOH / g, and pH 7.8. Visual stability assessment showed that the resulting aqueous dispersion did not settle out when stored at 60° C. for 4 weeks. The molecular weight of the synthesized copolymer was determined by gel permeation chromatography (GPC) using polystyrene calibration standards according to ASTM 3536 to be: number average molecular weight (Mn) 4300 Daltons; and weight average molecular weight (Mw) 16600 Daltons.

[0070] Synthesis Example 2 : Preparation of polyester polyol solution (PE1) A mixture of 911 g of trimethylolpropane, 748 g of hexahydrophthalic anhydride, and 138 g of dimer fatty acid (Empol S) 1008 (from Henkel) was heated to 250°C. Esterification was carried out with water separation until an acid value of less than 5 mg KOH / g was obtained. After cooling the reaction mixture to less than 125°C, the solids content was adjusted to 70% by weight with 90 g of xylene and 641 g of methoxypropyl acetate. The resulting polyester polyol had a calculated hydroxyl number of 345 mg KOH / g, an acid number of 4.5 mg KOH / g, a calculated hydroxyl functionality of 5.6, and a number average molecular weight (Mn) of 920 Daltons as measured by gel permeation chromatography (GPC) using polystyrene calibration standards according to ASTM 3536.

[0071] Example 1 Two-component (2K) clear coating compositions were prepared using the above dispersions (RSE1, SE1, PE1). Part a) of the two-component composition was obtained by mixing the ingredients shown in Table 1 below. Similarly, part b) of the two-component composition was obtained by blending Desmodur® N 3900 and butyl glycol acetate in the amounts shown. The table details the preparation of four reference coating compositions 1 (RCC1-RCC4); and two coating compositions according to the present disclosure (CC1-CC2). [Table 1]

[0072] The above-mentioned parts a) and b) were mixed in a mass ratio (a:b) of 100:35 to form coating compositions (RCC1-4, CC1-CC2). The molar ratio of active hydrogen atoms to -NCO groups (referred to herein as OH / NCO) ranged from 0.7:1 to 1.4:1. The viscosity of each composition was adjusted with deionized water to approximately 20-28 cps as measured at room temperature using a Brookfield CAP2000 viscometer (400 rpm, spindle No. 4). Each clearcoat coating composition was sprayed onto a black-coated steel panel and baked at 60°C for 30 minutes. The resulting coatings were subjected to the following evaluation tests, and the results are shown in Table 2 below. Wave Scan Wavescanning was performed using a Wavescan-DOI instrument available from BYK-Gardner GmbH, with the aim of simulating visual perception. The instrument provides a laser point source that illuminates the sample at a 60° angle, and an attached detector measures the reflected light intensity at the opposite, same angle. Long-wave signals (feature sizes >0.6 mm) and short-wave signals (feature sizes <0.6 mm) were each separated from the measured signal using a mathematical filter function. The instrument was rolled across the surface, measuring the optical profile of the surface point-by-point at predetermined intervals. The long-term waviness values ​​shown in Table 2 represent the variance of the long-wave signal amplitude and are normalized to a unitless value ranging from 0 to 100, with 0 representing the smallest variance (best) and 100 representing the largest variance (worst). Similarly, the short-term waviness values ​​represent the variance of the short-wave signal amplitude and are normalized to a unitless value ranging from 0 to 100. 0 represents the least variance (best) and 100 represents the most variance (worst).

[0073] Imageability (DOI)Distinctness-of-Image (DOI) Gloss: This is a measure of how clearly and sharply a reflected image appears in an applied coating and is measured herein using ASTM D5767-18 Standard Test Method for Instrumental Measurement of Distinctness-of-Image (DOI) Gloss of Coated Surfaces. This test method yields a rating ranging from 0 to 100, with 100 indicating perfect DOI (distinctness of image). As the value decreases from 100, the image becomes increasingly distorted.

[0074] Jacksonville Corrosivity Assessment Clearcoat corrosion evaluations were conducted by exposing five replicate clearcoat-coated steel panels (30 cm x 30 cm) to an exposure site on Blount Island, Jacksonville, Florida (USA). Exposure lasted from the end of May to the end of August. Defects were assessed using a scale of 1 (no visible corrosion) to 10 (severe corrosion) as detailed in GM Material Specification 9984157 (2009). The grades of the five replicates for each clearcoat were averaged to obtain the corrosion ratings shown in Table 2 below. [Table 2]

[0075] The addition of polyester resin to CC1 resulted in improved appearance compared to the reference coating compositions RCC1 and RCC2, as shown by the lower shortwave values ​​and higher DOI values ​​in Table 2. Additionally, CC1 showed improved Jacksonville corrosion resistance. The methacrylate copolymers used in CC1 and CC2 provided improved appearance compared to the reference coating compositions RCC3 and RCC4, respectively, as shown by the lower shortwave values ​​and higher DOI values ​​in Table 2. Additionally, CC1 and CC2 demonstrated improved Jacksonville corrosion resistance. The presence of the combination of low molecular weight diol and polyester resin in coating composition CC2 promotes improvements in both long-term and short-term waviness values ​​without compromising image clarity results or significantly compromising corrosion resistance.

[0076] It will be understood that various changes and modifications to the exemplary embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. Accordingly, such changes and modifications are intended to be covered by the appended claims. It will also be understood that the features of the dependent claims may be embodied in the respective compositions and methods of the independent claims. Many modifications and other embodiments of the disclosure set forth herein will come to mind to one skilled in the art to which this disclosure pertains once one has the benefit of the teachings of the foregoing description. It is to be understood, therefore, that the invention is not to be limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims.

Claims

1. 1. A two-component (2K) waterborne coating composition comprising: Water and a) a binder part comprising: (a1) at least one hydroxyl-functional (meth)acrylate copolymer; and (a2) at least one non-aromatic polyester having an active hydrogen group and, b) a crosslinker part comprising: At least one polyisocyanate compound having pendant NCO groups and, the molar ratio of active hydrogen atoms to —NCO groups in the composition is 5:1 to 1:5; the (a2) non-aromatic polyester has a number average molecular weight (Mn) of about 500 to about 5,000 Daltons, an acid number of about 0 to about 30 mg KOH / g, a calculated hydroxyl number of about 100 to about 600 mg KOH / g, and a calculated hydroxyl functionality of about 2 to about 8; The (a1) (meth)acrylate copolymer contains, based on the total mass of the monomers, from about 20 to about 60 wt. % of i) at least one hydroxyl-functional adduct of a monoepoxy ester and an unsaturated carboxylic acid; about 10 to about 30 wt. % of ii) at least one hydroxyl-functional unsaturated monomer different from component i); from about 2 to about 6 weight percent of iii) at least one unsaturated acid-functional monomer; and from about 20 to about 60% by weight of iv) at least one (meth)acrylate monomer represented by formula MA: H 2 C=CG a CO 2 R a (MA) [In the formula, G a is hydrogen, halogen or methyl; R a is C 1 ~C 18 Alkyl; C 2 ~C 18 Heteroalkyl; C 3 ~C 18 Cycloalkyl; C 2 ~C 8 Heterocycloalkyl; C 2 ~C 8 Alkenyl, or C 2 ~C 8 alkynyl]; from about 0 to about 15% by weight of v) at least one vinyl aromatic monomer; and about 0 to about 20% by weight of vi) at least one polymerizable unsaturated monomer different from i) to v); is a reaction product of monomers in the monomer mixture, comprising Two-component (2K) water-based coating compositions.

2. 10. The coating composition of claim 1, wherein the weight ratio of solids of (a1) to solids of (a2) is from about 100:1 to about 100:

35.

3. 3. The coating composition of claim 1 or 2, having a volatile organic compound (VOC) content of at most about 420 g / L, as measured according to ISO 11890-2:2006.

4. In formula (MA), R a is C 1 ~C 18 Alkyl or C 3 ~C 18 is cycloalkyl, The coating composition according to any one of claims 1 to 3.

5. 5. The coating composition of claim 1, wherein the (meth)acrylate monomer of formula (MA), when homopolymerized, produces a homopolymer having a glass transition temperature (Tg) greater than about 30°C.

6. 6. The coating composition of claim 5, wherein the at least one (meth)acrylate monomer is selected from cyclohexyl (meth)acrylate; 3,3,5-trimethylcyclohexyl (meth)acrylate; isobornyl (meth)acrylate; norbornyl (meth)acrylate; dihydrodicyclopentadienyl (meth)acrylate; 4-tert-butylcyclohexyl (meth)acrylate; and mixtures thereof.

7. The coating composition of any one of claims 1 to 6, wherein v) is present in an amount of about 4 to about 14 weight percent of the total weight of monomers in the monomer mixture.

8. 8. The coating composition of claim 7, wherein v) is present in an amount of about 10 to about 14 weight percent of the total weight of monomers in the monomer mixture.

9. The at least one vinyl aromatic monomer of v) has the formula (VA): 【Chemical 1】 In the formula, R 1 is H or C 1 ~C 4 is alkyl; Each R 2 are independently hydrogen or C 1 ~C 4 is alkyl; Ar is unsubstituted phenyl or phenyl substituted with 1 to 5 substituents, each substituent independently being halogen or C 1 ~C 4 is alkyl; n is an integer from 0 to 4; The coating composition according to any one of claims 1 to 8.

10. R 1 is H or methyl; Each R 2 is independently H or methyl; Ar is unsubstituted phenyl or phenyl substituted with 1 to 5 substituents, each substituent independently being halogen or C 1 ~C 4 is alkyl; n is 0 or 1; The coating composition of claim 9.

11. v) comprises at least one monomer selected from styrene; α-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 2-tert-butylstyrene; 4-tert-butylstyrene; 2-chlorostyrene; 4-chlorostyrene; and mixtures thereof; The coating composition of claim 9.

12. At least one monomer of the monomer mixture has the formula AM1: R 4 -C(H)=C(R 5 )-A-(R 6 O) [a] -R 7 (AM1) In the formula, R 4 is H, methyl, CO 2 H or CH 2 CO 2 H; R 5 is hydrogen, halogen or methyl; A is -CH 2 C(O)O-, -C(O)O-, -O-, -CH 2 O-, -CH 2 C(O)N-, -C(O)N-, -CH 2 -, -O-C(O)-, -NHCOO-, -NHCONH-, -C 6 H 4 (R 8 )-NH-C(O)-O-, -C 6 H 4 )(R 8 )-NH-C(O)-NH-, -C(O)O-CH 2 -CH(CH 2 OH)-O-, -C(O)O-CH 2 -CH(CH 2 OH)-NH-, -C(O)O-CH 2 -CH 2 -CH(OH)-O-, -C(O)O-CH 2 -CH 2 -CH(OH)-NH-, -CH 2 -O-CH 2 -CH(CH 2 OH)-O-, -CH 2 -O-CH 2 -CH 2 -CH(OH)-O-, -CH 2 -O-CH 2 -CH(CH 2 OH)-NH-, or -CH 2 -O-CH 2 -CH 2 -CH(OH)-NH-; Each R 6 is independently C 2 ~C 4 alkylene; [a] has a value of about 5 to about 100; R 7 is C 1 ~C 30 Alkyl, C 1 ~C 30 Hydroxyalkyl, C 1 ~C 30 Aminoalkyl, C 3 ~C 18 Cycloalkyl, C 2 ~C 5 Heterocycloalkyl, C 2 ~C 20 Alkenyl, C 2 ~C 12 Alkynyl, C 6 ~C 18 Aryl, C 7 ~C 24 Alkaryl or C 7 ~C 24 aralkyl; and R 8 is -CH 2 - or - (C) (CH 3 ) 2 -is, The coating composition according to any one of claims 1 to 11.

13. R 4 is H, methyl, CO 2 H or CH 2 CO 2 H; R 5 is hydrogen, halogen or methyl; A is -CH 2 -C(O)O- or -C(O)O-; Each R 6 are independently 2 ~C 4 alkylene; [a] has a value of about 10 to about 30; and R 7 is C 6 ~C 30 Alkyl, C 6 ~C 30 Hydroxyalkyl, C 6 ~C 30 Aminoalkyl, C 3 ~C 18 Cycloalkyl, C 6 ~C 18 Aryl, C 7 ~C 18 Alkaryl or C 7 ~C 18 It is aralkyl, The coating composition of claim 12.

14. R 4 is H, methyl, CO 2 H or CH 2 CO 2 H; R 5 is hydrogen, halogen or methyl; A is —C(O)O—; Each R 6 is independently C 2 ~C 3 alkylene; [a] has a value of about 10 to about 30; and R 7 is C 6 ~C 30 Alkyl, C 6 ~C 30 Hydroxyalkyl or C 6 ~C 30 is an aminoalkyl, The coating composition of claim 12.

15. the monomer having the formula AM1 is selected from lauryl ethoxylate [a] (meth)acrylate; cetyl ethoxylate [a] (meth)acrylate; stearyl ethoxylate [a] (meth)acrylate; behenyl ethoxylate [a] (meth)acrylate; lauryl ethoxylate [a] itaconate; cetyl ethoxylate [a] itaconate; stearyl ethoxylate [a] itaconate; behenyl ethoxylate [a] itaconate; lauryl ethoxylate [a] maleate; cetyl ethoxylate [a] maleate; stearyl ethoxylate [a] maleate; behenyl ethoxylate [a] maleate; and mixtures thereof; wherein [a] represents the number of moles of ethoxylation and has a value of from about 10 to about 30; The coating composition of claim 12.

16. The coating composition of any one of claims 1 to 15, wherein the (a1) hydroxyl-functional (meth)acrylate copolymer is prepared from the monomer mixture by a two-stage polymerization process.

17. the (a1) hydroxyl-functional (meth)acrylate copolymer is prepared from the monomer mixture by a skew-feed polymerization process using at least two feed monomer streams; Furthermore, one feed stream I) from about 60 to about 100% by weight of the total amount of i) in the monomer mixture; II) from about 0 to about 60% by weight of the total amount of ii) in the monomer mixture; III) from about 0 to about 30% by weight of the total amount of iii) in the monomer mixture; and, IV) from about 0 to about 80% by weight of the total amount of iv) in the monomer mixture; V) from about 0 to about 100% by weight of the total amount of v) in the monomer mixture; and, VI) from about 0 to about 100% by weight of the total amount of vi) in the monomer mixture; Including, the remaining one or more feed streams comprise the remainder of i) through vi); The coating composition according to any one of claims 1 to 16.

18. The non-aromatic polyester (a2) is a number average molecular weight (Mn) of about 500 to about 1500 Daltons; an acid value of about 0 to about 30 mg KOH / g; a calculated hydroxyl number of about 250 to about 400 mg KOH / g; and a calculated hydroxyl functionality of from about 4 to about 8; The coating composition according to any one of claims 1 to 17.

19. The non-aromatic polyester (a2) is at least one hydroxyl-functional component (a2h); at least one carboxyl-functional component (a2c); and, optionally, at least one hydroxycarboxylic acid component (a2hc), and The polycondensation reaction utilizes a stoichiometric excess of hydroxyl groups relative to carboxyl groups. The coating composition according to any one of claims 1 to 18.

20. The hydroxyl-functional component (a2h) may comprise, based on the weight of the hydroxyl-functional component: from about 75 to about 100% by weight of at least one polyol having 3 to 6 hydroxyl groups; and from about 0 to about 25% by weight of at least one diol; and The carboxyl functional component (a2c) may comprise, based on the weight of the carboxyl functional component: from about 75 to about 100% by weight of at least one dicarboxylic acid; and comprising from about 0 to about 25% by weight of at least one monocarboxylic acid; 20. The coating composition of claim 19.

21. 21. The coating composition of claim 20, wherein the at least one dicarboxylic acid comprises a dimer fatty acid in an amount of about 5 to about 50 weight percent based on the weight of the carboxyl-functional component.

22. Part a) further comprises, in an amount of up to 20% by weight, based on the weight of (a1), (a3) at least one (meth)acrylate polymer having an active hydrogen group different from the hydroxyl-functional (meth)acrylate polymer of (a1), wherein (a3) ​​has a water solubility of less than about 6 g / 100 mL at about 20°C; The coating composition according to any one of claims 1 to 21.

23. The (meth)acrylate polymer (a3) ​​is a calculated hydroxyl number of about 100 to about 600 mg KOH / g; an acid number of about 0 to about 35 mg KOH / g; and a number average molecular weight of about 1,000 to about 4,000 daltons; 23. The coating composition of claim 22.

24. The binder part a) may further comprise (a4) at least one non-polymeric acyclic polyol having a weight average molecular weight (Mw) of less than about 300 Daltons and a water solubility at about 20° C. of less than about 6 g / 100 mL; (a4) is present in an amount of up to 10% by weight, based on the weight of the binder part a); The coating composition according to any one of claims 1 to 23.

25. The binder part a) may further comprise (a5) at least one non-polymeric alicyclic polyol having a weight average molecular weight (Mw) of less than about 300 Daltons; (a5) is present in an amount of up to 10% by weight, based on the weight of the binder part a); The coating composition according to any one of claims 1 to 24.

26. 26. The coating composition of any one of claims 1 to 25, wherein the polyisocyanate compound of the crosslinker part b) contains 2 to 5 -NCO functional groups.

27. 27. The coating composition of any one of claims 1 to 26, wherein the molar ratio of active hydrogen atoms to --NCO groups in the composition is from about 3:1 to about 1:

3.

28. A cured product obtained from the aqueous coating composition of claim 1.

29. An article, a metallic substrate; a multi-layer coating disposed on the metallic substrate, wherein at least one layer of the multi-layer coating comprises the cured product of claim 28. Goods.

30. The multilayer coating comprises: a primer layer disposed on and in direct contact with the substrate; at least one basecoat layer comprising a color and / or visual effect imparting compound disposed over and in direct contact with the primer layer; a clear coat layer disposed on and in direct contact with at least one base coat layer, the clear coat layer comprising the cured product of claim 28; 30. The article of claim 29, comprising:

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