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

Abstract

A two-part (2K) waterborne coating composition comprising: water; a) a binder portion comprising: (a1) a hydroxyl-functional (meth)acrylate copolymer; and (a2) a non-aromatic polyester having active hydrogen groups; and b) a crosslinking agent portion comprising a polyisocyanate compound having -NCO side groups, wherein the (a2) non-aromatic polyester has a number average molecular weight (Mn) of 500 to 5000 Daltons, an acid value of 0 to 30 mg KOH / g, and an acid value of 100 to 600 mg KOH / g. The calculated hydroxyl value of KOH / g and the calculated hydroxyl functionality of 2 to 8; and the (a1) (meth)acrylate copolymer being a reaction product of a monomer mixture comprising: i) a hydroxyl-functionalized adduct of a monoepoxyester and an unsaturated carboxylic acid; ii) a hydroxyl-functionalized unsaturated monomer different from component i); iii) an unsaturated acid-functionalized monomer; and iv) a (meth)acrylate monomer represented by the formula H2C=CGaCO2Ra(MA).

Description

[Technical Field]

[0001] This disclosure relates to a two-part (2K) waterborne coating composition comprising a binder portion and a crosslinking agent portion. The binder portion comprises a water-dilutable hydroxyl-functional (meth)acrylate copolymer and a polyester having active hydrogen groups. The crosslinking agent portion of the composition comprises at least one polyisocyanate compound having -NCO side groups. This coating composition can be used as a transparent coating composition for application in vehicle finishing or refinishing. [Previous Technology]

[0002] Automotive repair refers to the composition and process used to repair damaged automotive topcoat (typically, but not necessarily, topcoat supplied by the original equipment manufacturer (OEM)). For example, a damaged automotive component may contain defective areas in which, at least partially, a previously applied coating has been removed, and such removal may in some cases expose the bare substrate of the component. Therefore, a repair operation may involve repairing or replacing an entire damaged automotive body component, repairing one or more coatings placed on such components, or a combination of both operations. The size of the defective area and the presence of a coating around the defective area generally determine the type of operation performed; if a coating is present, it can act as an anchor point for the repair paint composition.

[0003] Regarding coating repair, the repair process generally includes the following sequential steps: sanding the surface to be repaired; applying at least one layer of primer composition; sanding the applied primer composition as needed; applying at least one layer of basecoat composition to achieve the desired visual appearance, such as desired color, gloss or distinctiveness of image (DOI); and applying a clear coat composition, which should be transparent or translucent enough to allow the underlying coating to be seen through it.

[0004] In the past, paint compositions used for repair operations, including clear coat compositions, were solvent-based and therefore contained significant amounts of volatile organic compounds (VOCs). However, the use of these compounds is regulated. For example, in the United States, VOC emission standards are governed by Section 183(e) of the Clean Air Act (Act), and mandatory emission limits for automotive repair paints are subject to §7511b(e) of the United States Code (USC) and Subsection B of Part 59 of Title 40 of the Code of Federal Regulations (CFR).

[0005] In recent years, the coatings industry has made significant progress in complying with state and federal regulations regarding VOC emissions by developing solvent-based high-solids coating compositions and water-based coating compositions.

[0006] Compared to existing solvent-based alternatives, waterborne coating compositions may not only possess the wetting and leveling properties required for repair applications, but may also be easier for users to apply without requiring large-scale reuse of existing coating equipment. However, waterborne compositions must be dehydrated for proper crosslinking and curing. Given their boiling points, dehydration may be difficult to achieve via rapid drying, as dehydration conventionally requires fairly stringent baking conditions, in which careful control of air movement and humidity in the oven or drying chamber is necessary.

[0007] Since the drying of water-based compositions can be energy-intensive and may hinder the repair process, volatile organic co-solvents or diluents have been incorporated into these compositions to mitigate their drying properties. However, in the future, if the aforementioned regulations regarding the permissible levels of VOCs in automotive repair coating compositions become more stringent, the presence of such co-solvents and diluents may become undesirable.

[0008] Therefore, there is a need to develop waterborne coating compositions that exhibit properties comparable to their solvent-based counterparts. More specifically, such waterborne compositions should exhibit good leveling of the coated surface and be dehydrated under medium or low baking conditions during application. Furthermore, such compositions should exhibit suitable optical properties to facilitate their use in repair applications, and especially as their clear coating compositions.

[0009] Further beneficial features and properties of the various compositions will become apparent from the following detailed description and examples. [Summary of the Invention]

[0010] This disclosure provides a two-part (2K) waterborne coating composition comprising: water; a binder portion 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 crosslinking agent portion comprising: at least one polyisocyanate compound having -NCO side groups, wherein the molar ratio of active hydrogen atoms to -NCO groups in the composition is from about 5:1 to about 1:5; wherein the (a2) non-aromatic polyester has a number average molecular weight (Mn) of about 500 to about 5000 Daltons, an acid value of about 0 to about 30 mg KOH / g, a calculated hydroxyl value of about 100 to about 600 mg KOH / g, and a calculated hydroxyl functionality of about 2 to about 8; and wherein the (a1) (meth)acrylate copolymer is a reaction product of monomers in a monomer mixture, the monomer mixture comprising, based on the total weight of monomers: about 20 to about 60 wt.% of i) at least one hydroxyl-functionalized adduct of a monoepoxide ester and an unsaturated carboxylic acid; about 10 to about 30 wt.% of ii) at least one hydroxyl-functionalized unsaturated monomer different from component i); about 2 to about 6 wt.% of iii) at least one unsaturated acid-functionalized monomer; and about 20 to about 60 wt.% of iv) at least one (meth)acrylate monomer represented by the formula MA: H2C=CGaCO2Ra(MA) where: Ga is hydrogen, halogen or methyl; and Ra is: C1-C18 alkyl; C2-C18 heteroalkyl; C3-C18 cycloalkyl; C2-C8 heterocycloalkyl; C2-C8 alkenyl; or C2-C8 alkynyl; about 0 to about 15 wt.% of v) at least one vinyl aromatic monomer; and about 0 to about 20 wt.% of vi) at least one polymerizable unsaturated monomer different from i) to v).

[0011] This disclosure further provides a cured product obtained from the two-part (2K) waterborne coating composition.

[0012] This disclosure also provides an article comprising: a metal substrate; and a multilayer coating disposed on the metal substrate, wherein at least one layer of the multilayer coating comprises the cured product. In a key specific example of the article, the multilayer coating comprises: a primer layer disposed on the substrate and in direct contact with the substrate; at least one base coat layer comprising a compound imparting color and / or visual effect, wherein the base coat layer is disposed on the primer layer and in direct contact with the primer layer; and a clear coat layer comprising the cured product, wherein the clear coat layer is disposed on the base coat layer and in direct contact with the at least one base coat layer.

[0013] Where the forms described herein are specific examples, unless otherwise stated, any one or more of those specific examples may be implemented in or combined with any of the other specific examples, even if such combination is explicitly described. In other words, unless otherwise stated, the specific examples described are not mutually exclusive, and their substitutions remain within the scope of this disclosure.

Implementation Method

[0015] The following detailed description is exemplary in nature only and is not intended to limit the scope of this disclosure or its application and use. Furthermore, it is not intended to be bound by any theory presented in the foregoing prior art or the following detailed description.

[0016] Specific examples disclosed herein generally relate to water-dilutable hydroxyl-functional (meth)acrylate copolymers, compositions thereof, and methods of their formation. For the sake of brevity, prior art associated with such polymers and compositions may not be described in detail herein. Furthermore, the various tasks and process steps described herein may be incorporated into a more comprehensive procedure or process with additional steps or functionalities not described in detail herein. Specifically, the various steps for manufacturing such polymers and related compositions are well known; therefore, for the sake of brevity, prior art steps may be described only briefly or omitted entirely without providing well-known process details.

[0017] The polymers and compositions disclosed herein may suitably include, constitute, or substantially constitute the components, elements, and process descriptions described herein. Specific examples of the illustrative disclosure herein may suitably be practiced without any elements not specifically disclosed herein. Definitions

[0018] The term "consists essentially of" can describe various non-limiting specific examples that do not contain one or more of the compounds described herein, selected as needed, or one or more additives, solvents, polymers, resins, etc. not described herein but used in this art.

[0019] In various specific instances, the term "about" may describe values ​​of ±0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. Furthermore, it is to be understood in various non-limiting specific instances that, apart from actual examples, all numerical values ​​provided herein are approximate values, and their absolute or specific values ​​are intended to be interpreted as values ​​described "about" or "approximately".

[0020] The molecular weights mentioned in this specification are typically measured using polystyrene calibration standards by gel permeation chromatography (GPC), such as according to ASTM 3536.

[0021] As used herein, "acid value" is the mass of potassium hydroxide (KOH) in milligrams required to neutralize one gram of the composition described herein. Acid value can be determined by potentiometric analysis.

[0022] As used herein, the term "hydroxyl value" is defined as the mass, in milligrams, of potassium hydroxide required to neutralize the acetic acid absorbed during the acetylation of one gram of a chemical substance containing a free hydroxyl group. The hydroxyl value can be determined according to DIN 53240.

[0023] The term "active hydrogen atom" refers to a hydrogen atom that exhibits activity according to the Zerewitinoff test as described by Kohlerin J. Am. Chem. Soc., 49, 3181 (1927), which is expressly incorporated herein by reference in its entirety in various non-limiting specific examples. Active hydrogen atoms may originate from hydroxyl, thiol, primary amine, secondary amine, and carboxyl groups.

[0024] As used herein, the term softening point (°C) used with respect to wax is the Ring & Ball softening point, which is measured according to ASTM E28 unless otherwise indicated.

[0025] Unless otherwise specified, the viscosity of the compositions described herein shall be measured using a Brookfield Viscometer, model CAP2000, under standard conditions of 20°C and 50% relative humidity (RH). The viscometer shall be calibrated using a hydrocarbon oil of known viscosity, varying between 1 and 10,000 centipoise. A set of RV spindles attached to the viscometer shall be used for calibration. The coating composition shall be measured using spindle No. 4 at 400 rpm for 1 minute until the viscometer is balanced. The viscosity corresponding to the balance reading shall then be calculated using the calibration.

[0026] Unless otherwise stated, the term "particle size" refers to the largest axis of a particle. For a typical spherical particle, the largest axis is the diameter.

[0027] As used herein, the term "mean volume particle size" (Dv50) refers to the particle size corresponding to 50% of the sampled particles having a volume greater than and 50% of the sampled particles having a volume less than the Dv50 value. Similarly, if used, the term "Dv90" refers to the particle size corresponding to 90% of the sampled particles having a volume less than and 10% of the sampled particles having a volume greater than the Dv90 value. Particle size was determined herein using an Anton Paar Particle Size Analyzer (PSA) 1190 by laser diffraction.

[0028] As used herein, the room temperature is 23℃±2℃.

[0029] As used herein, "ambient conditions" means the environment in which the composition is situated or the environment in which the coating or the substrate of the coating is situated, including temperature and pressure.

[0030] In the context of this disclosure, "two-part (2K) compositions" should be understood as compositions in which a first part a) and a second part b) are stored in separate containers due to their (high) reactivity. The two parts are mixed before or during coating and then react, typically without additional activation and bond formation, to form a polymeric network structure. Higher temperatures may be applied herein to promote the crosslinking reaction.

[0031] As used herein, the term "water-dilutable (co)polymer" refers to a (co)polymer present in water in particulate form, which is generally stable for flocculation upon further dilution with water, either dispersed or suspended. In contrast to water-soluble (co)polymers, diluted solutions of water-dilutable polymers (approximately 1 g / L) exhibit scattering when analyzed using dynamic light scattering or any other particle analysis technique well known in this art.

[0032] The term "clear coat" is used herein to refer to a layer of paint that is transparent or translucent enough to allow the underlying layer to be seen through it. The term "transparent" does not require absolute transparency or translucency.

[0033] As used herein, “metallic” means any type of metal, metal alloy or mixture thereof. As used herein, the term “alloy” means a substance composed of two or more metals or metals and nonmetals, which are usually bonded together by melting them together and dissolving in each other during melting.

[0034] As used herein, unless otherwise expressly stated, the term "catalytic amount" means a substoichiometric amount of catalyst relative to the reactants.

[0035] As used herein, the term "free radical initiator" refers to a compound that, when exposed to sufficient energy (e.g., in the form of light or heat), decomposes into uncharged portions, each of which has at least one unpaired electron. Specifically, a free radical thermal initiator generates free radicals upon activation by thermal energy, such as heating or radiation in the infrared or microwave wavelength region.

[0036] It is explicitly intended that all isomers and chiral options of the compounds described herein be used in various non-limiting specific instances herein.

[0037] It should be understood that the subscripts for polymers typically describe average values, because the synthesis of polymers typically produces a distribution of various individual molecules.

[0038] As used herein, the term "monomer" means a substance that can undergo polymerization to provide structural units to the chemical structure of a polymer. As used herein, the term "monofunctional" means having one polymerizable moiety. As used herein, the term "polyfunctional" means having more than one polymerizable moiety.

[0039] As used herein, the term "blocked" refers to a compound having a "blocking group" that renders its reactive functionality unusable until the blocking group is removed or degraded. The blocking group can be selectively removed or degraded at appropriate points in the synthetic sequence: triggering events may include, in particular, moisture, heat, or radiation. Examples of blocked isocyanates include those that have been co-reacted with phenol, methyl ethyl ketone oxime, or ε-caprolactam.

[0040] As used herein, the term "fatty acid" is a monocarboxylic acid consisting of an aliphatic chain comprising 4 to 22 carbon atoms and a terminal carboxyl group (COOH). The fatty acid may 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 eiconsanoic acid.

[0041] The term "dimer fatty acid" is interchangeable with "dimerized fatty acid" and generally refers to a compound comprising two fatty acid subunits, wherein the individual fatty acid side chains are covalently bonded to each other by bonds or linking groups. Thus, as described herein, a dimer fatty acid dimer is a covalent fatty dimer. Dimer fatty acids can be heterodimers or homodimers and can be cyclic or acyclic. The term is intended to cover derivatives of dimer fatty acids having a functional carboxyl group that behave substantially similarly to dicarboxylic acids when reacting with diols and glycols to form polyesters: esters and reactive derivatives that form esters, such as acetic halides and anhydrides, may be mentioned.

[0042] As used herein, "(meth)acryl" is an abbreviation for "acryl" and / or "methacryl". Therefore, the term "(meth)acrylamide" refers to both acrylamide and methacrylamide.

[0043] As used herein, "C1-Cn alkyl" refers to a monovalent group or part thereof having 1 to n carbon atoms, i.e., an alkane group, and includes both straight-chain and branched organic groups. Therefore, "C1-C18 alkyl" refers to a monovalent group or part thereof having 1 to 18 carbon atoms, i.e., an alkane group, and includes both straight-chain and branched organic groups. Examples of alkyl groups include: methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; secondary butyl; tertiary butyl; n-pentyl; n-hexyl; n-heptyl; and 2-ethylhexyl. In this disclosure, such alkyl groups may be unsubstituted or may be substituted with one or more halogens. Where applicable to a given part (R), the tolerances for one or more non-halogen substituents within the alkyl group will be described in this specification.

[0044] As used herein, the term "C1-C18 hydroxyalkyl" refers to an HO-(alkyl) group having 1 to 18 carbon atoms, wherein the substituents are connected via an oxygen atom and the alkyl group is as defined above.

[0045] "alkoxy group" refers to a monovalent group represented by -OA, where A is an alkyl group; non-limiting examples include methoxy, ethoxy, and isopropoxy. As used herein, the term "C1-C18 alkoxyalkyl" refers to an alkyl group or part thereof having an alkoxy substituent as defined above and wherein the portion thereof (alkyl-O-alkyl) has a total of 1 to 18 carbon atoms; such groups include methoxymethyl (—CH2OCH3), 2-methoxyethyl (—CH2CH2OCH3), and 2-ethoxyethyl. Similarly, as used herein, the term "C7-C18 alkoxyaryl" refers to an aryl group having an alkoxy substituent as defined above and wherein the portion thereof (aryl-O-alkyl) contains a total of 7 to 18 carbon atoms.

[0046] As used herein, the term "C2-C4 alkylene" is defined as a saturated divalent hydrocarbon group having 2 to 4 carbon atoms.

[0047] The term "C3-C18 cycloalkyl" encompasses a saturated monocyclic or polycyclic hydrocarbon group or moiety having 3 to 18 carbon atoms. In this disclosure, such cycloalkyl groups or moiety may be unsubstituted or substituted with one or more halogens. When applied to a given moiety (R), the tolerance for one or more non-halogen substituents within the cycloalkyl group will be mentioned in this specification. Examples of cycloalkyl groups include: cyclopropyl; cyclobutyl; cyclopentyl; cyclohexyl; cycloheptyl; cyclooctyl; adamantane; and norbornene.

[0048] As used herein, "C2-C18 alkenyl" refers to a hydrocarbon group or portion having 2 to 18 carbon atoms and at least one alkene unsaturated unit. The alkenyl group or portion may be straight-chain, branched-chain, or cyclic, and may be substituted with one or more halogens as desired. When applicable to a given portion (R), the tolerance of one or more non-halogen substituents within the alkenyl group will be mentioned in this specification. As understood by those skilled in the art, the term "alkenyl" also encompasses groups having "cis" and "trans" configurations, or "E" and "Z" configurations. Examples of C2-C20 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; —CH2C H═CHCH2CH3;—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。

[0049] As used herein, "C6-C18 aryl" as used alone or as part of a larger part (e.g., in "aralkyl group") refers to monocyclic, bicyclic, and tricyclic systems, wherein the monocyclic system is aromatic, or at least one of the bicyclic or tricyclic systems is aromatic. Bicyclic and tricyclic systems include benzofused 2- or 3-membered carbon rings. In this disclosure, such aryl groups may be unsubstituted or may be substituted with one or more halogens. Where applicable to a given part (R), the tolerance of one or more non-halogen substituents within the aryl group will be mentioned in this specification. Exemplary aryl groups include: phenyl; (C1-C4)alkylphenyl, such as tolyl and ethylphenyl; indenyl; naphthyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthrayl; and anthracel.

[0050] As used herein, "alkylaryl" means an aryl group or part thereof that is alkyl-substituted, and "substituted alkylaryl" means an alkylaryl group or part thereof that is further carrying one or more substituents as described above. Furthermore, as used herein, "aralkyl" means an alkyl group or part thereof that is aryl-substituted as defined above.

[0051] As used herein, the term "hetero" refers to a group or part containing one or more heteroatoms such as N, O, Si, and S. Thus, by way of example, "heterocyclic" refers to a cyclic group having, for example, N, O, Si, or S as part of its ring structure. "Heteroalkyl," "heterocycloalkyl," and "heteraryl" parts are alkyl, cycloalkyl, and aryl groups as defined above, respectively containing N, O, Si, or S as part of their structure.

[0052] The term "non-polymeric" is used herein as a descriptive term for compounds that are not composed of repeating structural units. Non-polymeric compounds can be considered as unique, single structural units.

[0053] When used herein as a descriptive term for monomers, the term "non-aromatic" means a compound that does not have an aromatic core. This term is intended to include aliphatic and cycloaliphatic compounds, which may be saturated or unsaturated, in the latter case containing non-aromatic carbon-carbon double bonds or carbon-carbon triple bonds. Non-aromatic polymers may substantially lack an aromatic core in their backbone, such that the polymer may contain an aromatic core only due to technical impurities in the aliphatic or cycloaliphatic monomer building blocks.

[0054] As used herein, the term "base" refers to a substance that is capable of extracting protons in polar or nonpolar solvents; or that is capable of donating hydroxide anions (OH-).

[0055] In various specific instances, the term "free of" describes specific instances using an appropriate weight basis that would be understood by one of ordinary skill in the art, including less than about 5, 4, 3, 2, 1, 0.5, or 0.1 wt.% of the discussed component, compound, part, functional group, element, or ion. In other specific instances, the term "free of" describes specific instances having about 0 wt.% of the discussed component, compound, part, functional group, element, or ion.

[0056] As used herein, the term "anhydrous" is equivalent to the term "free of water".

[0057] Referring to the foregoing, the aqueous composition comprises water and: a) a binder portion; and b) a crosslinking agent portion. The water content, based on the weight of the composition, can be 30 to 80 wt.%. For example, the water content can be 35 to 70 wt.%, 40 to 60 wt.%, 45 to 55 wt.%, 45 to 52 wt.%, or 46 to 51 wt.%. At this water content, the drying and coalescence of the composition when coated onto a substrate may be independent of high energy and time costs. Compositions having this water content can be exemplified as having a viscosity of less than 500 centipoise, less than 200 centipoise, less than 100 centipoise, less than 50 centipoise, less than 40 centipoise, or even less than 30 centipoise, as measured at room temperature. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0058] The water in the two-part (2K) composition does not need to be added independently to any one or more components or the composition itself. Alternatively, one or more components of the composition may be provided in the water.

[0059] In certain specific examples, the binder portion a) of the two-part (2K) composition contains water, such that the binder portion a) provides at least a portion of the water in the two-part (2K) composition. However, it is not excluded that supplemental water may be added to the composition when or after the water-containing binder portion a) is placed together with the crosslinking agent portion b). This addition of supplemental water can be used to reduce the viscosity of the composition, which may be applicable to certain methods described below for coating the composition onto a substrate, such as spraying. Portion a)

[0060] Now referring to the binder portion a) of the two-part aqueous composition, this portion includes: (a1) at least one water-dilutable hydroxyl-functional (meth)acrylic acid copolymer; and (a2) at least one non-aromatic polyester having active hydrogen groups.

[0061] At least one hydroxyl-functional (meth)acrylate copolymer of component (a1) is water-dilutable, but typically compatible with polyisocyanates (including hydrophobic polyisocyanates not modified with hydrophilic groups, particularly polyether or polyester groups). Therefore, the two-part coating composition itself is water-dilutable, which provides flexibility for the operator when applying the coating composition, for example, in vehicle repair operations. Furthermore, it is believed that this amount of vinyl aromatic monomer promotes the miscibility of the hydroxyl-functional (meth)acrylate copolymer and the polyisocyanate, thereby maintaining the dispersion stability of the copolymer and providing a better appearance for the final cured coating.

[0062] The presence of a non-aromatic polyester in the binder portion of the composition improves the appearance of the cured coating obtained therefrom. The non-aromatic polyester also contributes to the weather resistance of the cured coating. Copolymer component (a1)

[0063] The (meth)acrylate copolymer is a reaction product of a monomer mixture, which, based on the total weight of the monomers in the monomer mixture, comprises: 20 to 60 wt.% of i) at least one hydroxyl-functionalized adduct of a monoepoxide ester and an unsaturated carboxylic acid; 10 to 30 wt.% of ii) at least one hydroxyl-functionalized unsaturated monomer different from component i); 2 to 6 wt.% of iii) at least one unsaturated acid-functionalized monomer; 20 to 60 wt.% of iv) at least one (meth)acrylate monomer represented by the formula MA: H2C=CGaCO2Ra(MA) where: Ga is hydrogen, halogen, or methyl; and Ra is: C1-C18 alkyl; C2-C18 heteroalkyl; C3-C18 cycloalkyl; C2-C8 heterocycloalkyl; C2-C8 alkenyl; or C2-C8 alkynyl; 0 to 15 wt.% of v) at least one vinyl aromatic monomer; and 0 to 20 wt.% of vi) at least one polymerizable unsaturated monomer different from monomer components i) to v). Monomer component i): hydroxyl-functional adduct.

[0064] Based on the total weight of monomers in the monomer mixture, the monomer mixture includes 20 to 60 wt.% of i) at least one hydroxyl-functionalized adduct of a monoepoxide ester and an unsaturated carboxylic acid. For example, based on the total weight of monomers in the monomer mixture, the monomer mixture may contain 30 to 60 wt.% or 40 to 60 wt.% of i) at least one adduct. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0065] Typically, the adduct is formed via a nucleophilic addition reaction of a monoepoxide ester with an acid to form a hydroxyalkyl ester. This acid ring-opening reaction conventionally requires a catalyst, with tertiary amines, quaternary ammonium compounds, and transition metal compounds mentioned as examples.

[0066] The reactant monoepoxide is typically a glycidyl ester derived from an aliphatic saturated monocarboxylic acid having a tertiary or quaternary carbon atom at the α (alpha) position. Representative reactant monoepoxides are glycidyl esters of saturated α,α-dialkyl alkane monocarboxylic acids having 5 to 13 carbon atoms or 9 to 11 carbon atoms in the acid molecule. Exemplary reactant monoepoxides include: glycidyl versatic acid, commercially available from Hexion as Cardura E10; glycidyl tertivalate, commercially available from Hexion as Cardura E5; and reaction products of up to 12 carbon atoms in a tertiary fatty acid with epichlorohydrin.

[0067] The reactant acid-functionalized compound may be an aliphatic unsaturated monocarboxylic acid, with non-limiting examples including: α,β-mono-alkenyl unsaturated monocarboxylic acids, such as acrylic acid, methacrylic acid, butenoic acid, and isocrotonic acid; C1-C6 alkyl half-esters of α,β-mono-alkenyl unsaturated dicarboxylic acids (such as fumaric acid and maleic acid); and C1-C6 alkyl esters of α,β-mono-alkenyl unsaturated tricarboxylic acids carrying a free carboxylic acid group. In various specific examples, acrylic acid and / or methacrylic acid are used as reactant acid-functionalized compounds. Monomer component ii): Hydroxyl-functionalized alkenyl unsaturated monomer

[0068] Based on the total weight of monomers in the monomer mixture, the monomer mixture contains 10 to 30 wt.% of ii) at least one hydroxyl-functionalized monomer different from monomer component i). For example, based on the total weight of monomers in the monomer mixture, the monomer mixture may contain 10 to 25 wt.% or 10 to 20 wt.% of ii) at least one hydroxyl-functionalized monomer. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0069] Exemplary monomers of component ii) include hydroxyalkyl esters having a primary or secondary hydroxyl group derived from an α,β-monoolefinic unsaturated monocarboxylic acid. Such hydroxyalkyl esters may include, for example, hydroxyalkyl esters derived from acrylic acid, methacrylic acid, crotonic acid, or isocrotonic acid.

[0070] In a specific example, monomer component ii) comprises at least one hydroxy (meth)acrylate monomer represented by the formula HMA: H2C=CGaCO2Rh (HMA) Wherein: Ga is hydrogen, halogen or methyl; and Rh is C1-C18 hydroxyalkyl.

[0071] Typical monomers according to formula HMA are monomers in which: Ga is hydrogen, halogen, or methyl; and Rh is C1-C12 hydroxyalkyl. Monomers in which Ga is hydrogen or methyl and Rh is C1-C6 hydroxyalkyl may also be used.

[0072] Examples of (meth)acrylate monomers according to 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. Monomer component iii): Alkenyl unsaturated acid functional monomers

[0073] Based on the total weight of the monomers in the monomer mixture, the monomer mixture also contains 2 to 6 wt.% of iii) at least one olefinic unsaturated acid functional monomer. For example, component iii) may account for 2 to 5 wt.% or 2 to 4 wt.% of the monomer mixture. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those set forth above) be used herein.

[0074] Without limiting the scope of this disclosure, the unsaturated acid functional monomer may be selected from: olefinic unsaturated carboxylic acids; olefinic unsaturated sulfonic acids; vinylphosphonic acids; and mixtures thereof. Suitable olefinic unsaturated sulfonic acids include, for example, vinyl sulfonic acid, styrene sulfonic acid, and acrylamide methylpropanesulfonic acid.

[0075] Typically, monomer component iii) comprises at least one olefinic unsaturated carboxylic acid selected from the following: α,β-mono-olefinic unsaturated monocarboxylic acid; α,β-mono-olefinic unsaturated dicarboxylic acid; C1-C6 alkyl half-esters of α,β-mono-olefinic unsaturated dicarboxylic acid; α,β-mono-olefinic unsaturated tricarboxylic acid; C1-C6 alkyl esters of α,β-mono-olefinic unsaturated tricarboxylic acid carrying at least one free carboxylic acid group; and mixtures thereof. Specifically, monomer component iii) may comprise at least one olefinic unsaturated carboxylic acid selected from methacrylic acid, acrylic acid, itconic acid, maleic acid, aconitic acid, crotonic acid, fumaric acid, and mixtures thereof.

[0076] For completeness, although the unsaturated acid-functionalized monomers described above can be used in free acid form, it is not excluded that the constitutive acid groups of the monomers may be partially or completely neutralized with a suitable base, provided that their participation in the copolymerization reaction is not impaired. Monomer component iv): (meth)acrylate monomer of formula MA

[0077] Based on the total weight of the monomers in the monomer mixture, the monomer mixture also contains 20 to 60 wt.% of iv) at least one (meth)acrylate monomer represented by the formula MA: H2C=CGaCO2Ra(MA) Wherein: Ga is hydrogen, halogen or methyl; and Ra is: C1-C18 alkyl; C2-C18 heteroalkyl; C3-C18 cycloalkyl; C2-C8 heterocycloalkyl; C2-C8 alkenyl; or C2-C8 alkynyl.

[0078] For example, based on the total weight of the monomers in the monomer mixture, the monomer mixture may contain 25 to 50 wt.% of (iv) at least one (meth)acrylate monomer represented by formula MA. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0079] In a typical monomer according to formula MA: Ga is hydrogen, halogen, or methyl; and Ra is C1-C18 alkyl or C3-C18 cycloalkyl. Monomers in which Ga is hydrogen or methyl may also be used.

[0080] Examples of (meth)acrylate monomers according to formula MA that can be used alone or in combination include: methyl (meth)acrylate; ethyl (meth)acrylate; n-butyl (meth)acrylate; isobutyl (meth)acrylate; hexyl (meth)acrylate; 2-ethylhexyl (meth)acrylate; isodecanyl (meth)acrylate; dodecyl (meth)acrylate; lauryl (meth)acrylate; stearyl (meth)acrylate; cyclohexyl (meth)acrylate; 3,3,5-trimethylcyclohexyl (meth)acrylate; 4-tert-butylcyclohexyl (meth)acrylate; isocamphenyl (meth)acrylate; norcamphenyl (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.

[0081] In some specific instances, the (meth)acrylate monomers constituting component iv) of the monomer mixture may include "hard" monomers. The term "hard monomer" typically describes a monomer that, upon homopolymerization, will produce a homopolymer with a glass transition temperature (Tg) above about 30°C. For example, monomer component iv) may contain at least one (meth)acrylate monomer that would be considered a hard monomer.

[0082] Exemplary hard monomers include: cyclohexyl (meth)acrylate; 3,3,5-trimethylcyclohexyl (meth)acrylate; isoborneol (meth)acrylate; norborneol (meth)acrylate; dihydrodicyclopentadienyl (meth)acrylate; and 4-tert-butylcyclohexyl (meth)acrylate. Monomer component v): Vinyl aromatic monomers selected as needed.

[0083] Based on the total weight of monomers in the monomer mixture, the monomer mixture may also contain 0 to 15 wt.% (v) at least one vinyl aromatic monomer. For example, based on the total weight of monomers in the monomer mixture, the monomer mixture may contain 4 to 14 wt.%, 8 to 14 wt.%, or 10 to 14 wt.% (v) at least one vinyl aromatic monomer. Alternatively, it may not contain this monomer at all. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0084] In a specific example, monomer component v) comprises at least one vinyl aromatic monomer of formula (VA): wherein: R1 is H or C1-C4 alkyl; each R2 is independently hydrogen or C1-C4 alkyl; Ar is an unsubstituted phenyl or a phenyl substituted with 1 to 5 substituents, wherein each substituent is independently halogen or C1-C4 alkyl; and n is an integer from 0 to 4.

[0085] A typical monomer according to formula VA is a monomer in which: R1 is H or methyl; each R2 is independently H or methyl; Ar is an unsubstituted phenyl or a phenyl substituted with 1 to 5 substituents, wherein each substituent is independently halogen or C1-C4 alkyl; and n is 0 or 1.

[0086] Exemplary vinyl aromatic monomers of formula (VA) that can be used alone or in combination include: styrene; α-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 2-tributylstyrene; 4-tributylstyrene; 2-chlorostyrene; and 4-chlorostyrene. Monomer component vi): Other monomers selected as needed.

[0087] Based on the total weight of monomers in the monomer mixture, the monomer mixture may also contain 0 to 25 wt.% of at least one polymerizable unsaturated monomer different from monomer components i) to v). For example, based on the total weight of monomers in the monomer mixture, the monomer mixture may contain 0 to 20 wt.%, 1 to 20 wt.%, or 5 to 20 wt.% of at least one polymerizable unsaturated monomer different from monomer components i) to v). In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0088] Exemplary monomers of component vi) which may be used alone or in combination include: aromatic (meth)acrylate monomers; (meth)acrylate functionalized oligomers; nitrogen (N-) functionalized olefinic unsaturated monomers; silane functionalized olefinic unsaturated monomers, such as methacryloyloxypropyltris(C1-C5)alkoxysilane and vinyltris(C1-C5)alkoxysilane; acetylacetyl functionalized unsaturated monomers, such as acetylacetyloxymethyl 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 oxoalkane polyols; and poly(C2-C3)alkyldiol di(meth)acrylates.

[0089] Suitable aromatic (meth)acrylate monomers include monomers represented by the formula AII: H2C=CGbCO2Rb (AII) Wherein: Gb is hydrogen, halogen or methyl; and Rb is C6-C18 aryl, C1-C9 heteroaryl, C7-C18 alkoxyaryl, C7-C18 alkylaryl or C7-C18 aralkyl.

[0090] Exemplary (meth)acrylate monomers according to formula (AII) that can be used alone or in combination include: (meth)acrylate benzyl acrylate; (meth)acrylate phenoxyethyl acrylate; and (meth)acrylate phenoxypropyl acrylate.

[0091] Suitable (meth)acrylate-functionalized oligomers may be selected from (meth)acrylate-functionalized polyurethanes, (meth)acrylate-functionalized polybutadiene, (meth)acrylate polyol (meth)acrylates, polyester (meth)acrylate oligomers, polyamide (meth)acrylate oligomers, polyether (meth)acrylate oligomers, and mixtures thereof. These oligomers may have one or more acrylate and / or methacrylate groups attached to the oligomer backbone, the (meth)acrylate functional groups being located at the end of the oligomer and / or distributed along the oligomer backbone. Typically, the (meth)acrylate-functionalized oligomer is a monomer reaction-derived copolymer (a1): each molecule has two or more (meth)acrylate functional groups; and / or has a weight average molecular weight (Mw) of about 300 to about 1000 Daltons. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0092] Regarding (N-)functionalized olefinic unsaturated monomers, the nitrogen functionalization group may be a nitrile or a urea, or may include an imine, amide or amine nitrogen atom.

[0093] Exemplary nitrile monomers include acrylonitrile and methacrylonitrile. Exemplary maleic diimide monomers include: maleic diimide; methyl maleic diimide; ethyl maleic diimide; propyl maleic diimide; butyl maleic diimide; hexyl maleic diimide; octyl maleic diimide; dodecyl maleic diimide; octadecyl maleic diimide; phenyl maleic diimide; and cyclohexyl maleic diimide. Exemplary (meth)acrylamides include: acrylonitrile; diacetone (meth)acrylamide; N-methyl (meth)acrylamide; N-ethyl (meth)acrylamide; N-isopropyl (meth)acrylamide; N-tert-butyl (meth)acrylamide; N-hexyl (meth)acrylamide; N-cyclohexyl (meth)acrylamide; N-octyl (meth)acrylamide; N-tert-octyl (meth)acrylamide; N-dodecyl (meth)acrylamide; N-benzyl (meth)acrylamide; N-(hydroxymethyl)acrylamide; N-isobutoxymethylacrylamide; N-butoxymethylacrylamide; N,N-dimethyl (meth)acrylamide; N, N-Diethyl(meth)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; acrylamide-2-methylpropane sulfonate; and N,N'-methylenebisacrylamide.

[0094] It is not excluded that the copolymer (a1) includes residues of at least one amino (meth)acrylate monomer. As used herein, the term "amino (meth)acrylate" refers to methacrylic acid or a derivative of acrylic acid having a primary, secondary, or tertiary amino group: the amino group may be a straight-chain, branched-chain, or cyclic aliphatic or aromatic group portion. The at least one amino (meth)acrylate monomer may be a tertiary amino (meth)acrylate, particularly such as N,N-dialkylaminoalkyl (meth)acrylate. In various specific examples, one or more of N,N-dimethylaminoethyl methacrylate, N,N-dimethylaminoethyl methacrylate, N,N-dimethylaminopropyl methacrylate, or N,N-dimethylaminopropyl acrylate may be used.

[0095] In another non-limiting specific example, the monomer mixture includes at least one ethylene-type monomer having a nitrogen heterocyclic structure. Exemplary heterocyclic structures have 5 or 6 members and may also contain oxygen atoms in addition to nitrogen: the 5 or 6-membered ring may, for example, represent a pyridine, pyrimidine, thiazoline, imidazoline, imidazole, oxazolinite, oxazolium, or thiazoline ring. Examples that can be used alone or in combination include: N-vinylcaprolactam (NVC); vinyl methyl oxazolidinone (VMOX); N-vinylmethylamine; N-vinylcarbazole; N-vinylacetamide; and N-vinylpyrrolidone.

[0096] Exemplary copolymerizable vinyl esters in this disclosure include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and monomers of the VEOVA™ series available from Shell Chemical. Exemplary copolymerizable poly(meth)acrylates of alkane polyols include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, and neopentyl tert-tetra(meth)acrylate. Exemplary poly(meth)acrylates of copolymerizable oxoalkane polyols include diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dibutyl glycol di(meth)acrylate, and di(pentanediol) dimethacrylate.

[0097] In one specific example, the monomer mixture comprises at least one monomer having the general formula AM1: R4-C(H)═C(R5)—A—(R6O)[a]—R7(AM1) Wherein: R4 is H, methyl, CO2H or CH2CO2H; R5 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(R8)-NH-C(O)-O-, -C6H4(R8)-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(CH2 OH)-O-, -CH2-O-CH2-CH2-CH(OH)-O-, -CH2-O-CH2-CH(CH2OH)-NH- or -CH2-O-CH2-CH2-CH(OH)-NH-; Each R6 is independently a C2-C4 alkylene; [a] has a value of 5 to 100; R7 is a C1-C30 alkyl, C1-C30 hydroxyalkyl, C1-C30 aminoalkyl, C3-C18 cycloalkyl, C2-C5 heterocycloalkyl, C2-C20 alkenyl, C2-C12 alkynyl, C6-C18 aryl, C7-C24 alkylaryl or C7-C24 aralkyl; and R8 is -CH2- or -(C)(CH3)2-.

[0098] A typical monomer according to formula AM1 is a monomer in which: R4 is H, methyl, CO2H or CH2CO2H; R5 is hydrogen, halogen or methyl; A is -CH2C(O)O- or -C(O)O-; each R6 is independently C2-C4 alkylene; [a] has a value of 10 to 30; and R7 is C6-C30 alkyl, C6-C30 hydroxyalkyl, C6-C30 aminealkyl, C3-C18 cycloalkyl, C6-C18 aryl, C7-C18 alkylaryl or C7-C18 aralkyl.

[0099] A representative monomer according to formula AM1 is a monomer in which: R4 is H, methyl, CO2H or CH2CO2H; R5 is hydrogen, halogen or methyl; A is -C(O)O-; each R6 is independently C2-C3 alkylene; [a] has a value of 10 to 30; and R7 is C6-C30 alkyl, C6-C30 hydroxyalkyl or C6-C30 aminealkyl.

[0100] Exemplary monomers according to formula AM1 that can be copolymerized alone or in combination include: (meth)acrylate lauryl ethoxide [a]; (meth)acrylate cetyl ethoxide [a]; (meth)acrylate stearyl ethoxide [a]; (meth)acrylate docosyl ethoxide [a]; itconic acid lauryl ethoxide [a]; itconic acid cetyl ethoxide [a]; itconic acid stearyl ethoxide [a]; itconic acid docosyl ethoxide [a]; maleic acid lauryl ethoxide [a]; maleic acid cetyl ethoxide [a]; maleic acid stearyl ethoxide [a]; and maleic acid docosyl ethoxide [a], wherein [a] represents an ethoxide mole number and has a value of 10 to 30. In other words, each of the above can be described as an ethoxide compound having an ethoxide degree of 10 to 30 moles of ethylene oxide. In some specific instances, the parameter [a] may have values ​​from 15 to 30 or from 15 to 25. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0101] Hydroxyl-functional (meth)acrylic acid copolymers are typically produced by free radical solution copolymerization, wherein monomers are produced in a solution of a solvent that is also capable of dissolving the copolymer, wherein the monomers are polymerized by free radicals, i.e., polymerized in the presence of a free radical initiator. Generally, the aforementioned monomers are typically loaded into a reflux reactor in the presence of at least one organic solvent and a free radical initiator. The concentration of monomers in the solution may vary, but the weight ratio of monomers to solvent will typically be from 1:20 to 2:1, for example from 1:2 to 1.5:1. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0102] Typically, known polymerization conditions are utilized, and these conditions include temperatures ranging from 25 to 250°C (e.g., 50 to 250°C or 75 to 250°C). Polymerization pressure is generally not critical; therefore, polymerization can be carried out at sub-atmospheric, atmospheric, or super-atmospheric pressures. If necessary, polymerization can be carried out in the absence of oxygen: the reaction vessel may be equipped with an inert, dry gaseous covering layer, such as nitrogen, helium, or argon. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0103] Conventionally, based on the total weight of the polymerizable monomers, the amount of at least one free radical initiator is 0.1 to 1 wt.%, for example, 0.1 to 0.5 wt.%. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0104] A typical class of suitable free radical initiators is organic peroxides, selected from, for example: cyclic peroxides; diacyl peroxides; dialkyl peroxides; hydroperoxides; peroxy carbonates; peroxy dicarbonates; peroxy esters; and peroxy ketals.

[0105] 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 organic hydroperoxides. For completeness, the definition of hydroperoxide includes materials that decompose or hydrolyze to form organic hydroperoxides in situ, such as organic peroxides or organic peresters: examples of such peroxides and peresters are cyclohexyl and hydroxycyclohexyl peroxides and tributyl perbenzoate, respectively.

[0106] In one specific example of this disclosure, the free radical initiator comprises at least one hydroperoxide compound represented by the formula: RpOOH, wherein: Rp is an aliphatic or aromatic group containing up to 18 carbon atoms, and typically wherein: Rp is a C1-C12 alkyl, C6-C18 aryl or C7-C18 aralkyl.

[0107] One or more free radical initiators may include: cumene hydroperoxide (CHP); p-butyl hydroperoxide; t-butyl hydroperoxide. (hydroperoxide; TBH); tert-butyl perbenzoate; tert-butyl peroxypentanoate; di-tert-butanol peroxide; tert-butyl peracetic acid; tert-butyl peroxy-2-hexanoate; tert-pentanol hydroperoxide; 1,2,3,4-tetramethylbutanol hydroperoxide; benzoyl peroxide; dibenzoyl peroxide; 1,3-bis(tert-butylperoxyisopropyl)benzene; diacetyl peroxide; 4,4-bis(tert-butylperoxy)pentanoate; p-chlorobenzoyl peroxide; tert-butyl isopropylbenzene peroxide; di-tert-butanol peroxide; diisopropylbenzene peroxide; 2,5-dimethyl-2,5-di-tert-butylperoxyhexane; 2,5-dimethyl-2,5-di-tert-butyl-peroxyhex-3-yne; and 4-methyl-2,2-di-tert-butylperoxypentane.

[0108] Azo polymerization initiators may also be used, and such initiators may be selected from: azonitrile; azo ester; azoamide; azomididine; azoimidazoline; macro azo initiator; and combinations thereof.

[0109] 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-formitrile); 4,4'-azobis(4-cyanopentanoic acid); 2,2'-azobis(2-methylpropionic acid) dimethyl ester; 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]; 2,2 '-Azobis(N-butyl-2-methylpropane); 2,2'-Azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride; 2,2'-Azobis[2-(2-imidazolin-2-yl)propane]; 2,2'-Azobis(2-methylpropanediamine) dihydrochloride; 2,2'-Azobis[N-(2-carboxyethyl)-2-methylpropanediamine] tetrahydrate; 4,4-Azobis(4-cyanopentanoic acid), a polymer having 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.).

[0110] Redox initiators may also be used, and such redox initiators include combinations of oxidants and reductants. Suitable oxidants may be selected from cyclic peroxides, diacyl peroxides, dialkyl peroxides, hydroperoxides, peroxy carbonates, peroxy dicarbonates, peroxy esters, peroxy ketals, and mixtures thereof. Corresponding reductants may be selected from: alkali metal sulfites; alkali metal bisulfites; alkali metal metabisulfites; formaldehyde hyposulfites; alkali metal salts of aliphatic sulfinic acids; alkali metal hydrosulfides; polyvalent metal salts, especially Co(II) and Fe(II) salts, such as ferric(II) sulfate, ferric(II) ammonium sulfate, or ferric(II) phosphate; dihydroxymaleic acid; benzoin; ascorbic acid; reducing sugars, such as sorbitol, glucose, fructose, and / or dihydroxyacetone; and mixtures thereof.

[0111] Free radical polymerization can be carried out in the presence of chain transfer agents, which are used to transfer free radicals and reduce the molecular weight of the resulting polymer and / or control chain growth during polymerization. When added, the chain transfer agent may comprise 0.01 to 1 wt.% of the mixture based on the total weight of the polymerizable monomers. The amount of polymerization initiator and any chain transfer agent present will affect the number-average molecular weight of the (co)polymer, but the choice of solvent may also be taken into account. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0112] Free radical polymerization reactions are typically carried out in organic solvents (typically polar solvents). Measured at 1 atmosphere (1.01325 bar), an effective polar solvent may have a boiling point of at least 20°C (e.g., at least 30°C or at least 40°C). Examples of such polar solvents that can be used alone or in combination include: C1-C8 alkanols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, di-butanol, and isobutanol; acetonitrile; N,N-di(C1-C4)alkylamides, such as N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAc); hexamethylphosphatamide; N-methylpyrrolidone; pyridine; esters, such as (C1-C8)alkyl acetate, ethoxydiethylene acetate, dimethyl glutarate, dimethyl maleate, dipropyl oxalate, ethyl lactate, benzoyl benzoate, butyl octyl benzoate, and ethylhexyl benzoate; ketones, such as acetone, ethyl ketone, and methyl ethyl ketone (2- Butanone (MEK) and methyl isobutyl ketone; ethers, such as tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), and 1,2-dimethoxyethane; 1,3-dioxacyclopentane; dimethylsulfoxide (DMSO); and dichloromethane (DCM). In an exemplary specific example, the polymerization reaction is carried out in the presence of alkyl esters of acetate (C1-C8), such as ethyl acetate.

[0113] The hydroxyl-functional (meth)acrylate copolymer (a1) can be prepared from a monomer mixture by a skew-feed polymerization method having at least two monomer feed streams. In a specific example, the first feed stream comprises: I) 60 to 100% by weight of component i) based on the total amount of the hydroxyl-functional adduct i) of the monoepoxide and unsaturated carboxylic acid in the monomer mixture; II) 0 to 60% by weight of monomer ii) based on the total amount of the hydroxyl-functional unsaturated monomer ii) in the monomer mixture; III) 0 to 30% by weight of monomer iii) based on the total amount of the unsaturated acid-functional monomer iii) in the monomer mixture; IV) 0 to 80% by weight of monomer iv) based on the total amount of at least one (meth)acrylate monomer represented by formula MA in the monomer mixture; V) 0 to 100% by weight of monomer v) based on the total amount of at least one vinyl aromatic monomer in the monomer mixture; and VI) 0 to 100% by weight of monomer vi) based on the total amount of other polymerizable unsaturated monomer vi) in the monomer mixture. The remaining one or more feed streams contain the balance of monomer components i) to vi). In various non-limiting specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) are used herein.

[0114] In this type of skew-feed polymerization, the total amount of radical initiator to be added can be fully charged at the start of the first feed step. However, typically, portions of the radical initiator are charged over time, and more specifically, one portion is charged in each feed stream. The initiator dissociation portions dedicated to a particular feed stream added to the reflux reactor can be introduced as a single dose, stepwise, or continuously.

[0115] Similarly, the total amount of organic solvent can be fully charged at the start of the first feed step. However, typically, portions of the organic solvent are charged over time, and more specifically, one portion is charged in each feed stream. Conventionally, the solvent portion dedicated to a particular feed stream can be added to the reflux reactor before or simultaneously with the start of monomer addition.

[0116] In certain specific examples of skew-feed polymerization, the reactor contents may be flushed with an organic solvent after the addition of the first feed stream. Intermediate flushing steps may similarly be performed between subsequent feed steps.

[0117] The progress of the polymerization reaction and its various feed steps, when applicable, can be monitored by potentiometric titration to determine the hydroxyl value and / or acid value. When these values ​​reach a predetermined value based on the desired conversion level, the reactor contents are typically cooled, and then partially or completely neutralized by adding an appropriate amount of alkali. The reactor contents containing the hydroxyl-functional (meth)acrylate copolymer polymer (a1) can then be converted into an aqueous dispersion by normal or reverse dilution with water. Component (a2)

[0118] The binder portion of the two-part (2k) composition disclosed herein a) comprises (a2) at least one non-aromatic polyester having an active hydrogen group, wherein the non-aromatic polyester has: a number average molecular weight (Mn) of about 500 to about 5000 Daltons; an acid value of about 0 to about 30 mg KOH / g; a calculated hydroxyl value of about 100 to about 600 mg KOH / g; and a calculated hydroxyl functionality of about 2 to about 8. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those set forth above) be used herein.

[0119] In important specific examples, the non-aromatic polyester (a2) has: 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 value of about 250 to about 400 mg KOH / g; and a calculated hydroxyl functionality of about 4 to about 8. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those set forth above) be used herein.

[0120] Typically, the weight ratio of the solids of component (a1) hydroxyl-functional (meth)acrylate copolymer to the solids of component (a2) polyester is from about 100:1 to about 100:35, such as 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 specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0121] Non-aromatic polyesters are typically prepared by polycondensation of at least one hydroxyl-functional component (a2h); at least one carboxyl-functional component (a2c); and, if desired, at least one hydroxycarboxylic acid component (a2hc). These components can be selected according to type and amount so that the non-aromatic polyester obtains the molecular weight, acid value, hydroxyl value, and functionality mentioned above. Generally, the polycondensation reaction can be exemplified by a stoichiometric excess of hydroxyl relative to carboxyl. Typically, the stoichiometric excess of hydroxyl relative to carboxyl can be 5 to 40 mol.%, such as 5 to 35 mol.%, 5 to 30 mol.%, or 5 to 25 mol.%. In various non-limiting specific examples, it is explicitly considered that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) are used herein.

[0122] Based on the weight of the hydroxyl-functional component, the hydroxyl-functional component (a2h) may comprise: 75 to 100 wt.%, such as 80 to 100 wt.% or 90 to 100 wt.%, of at least one polyol having 3 to 6 hydroxyl groups; and 0 to 25 wt.%, such as 0 to 20 wt.% or 0 to 10 wt.%. In some specific examples, based on the weight of the hydroxyl-functional component, the hydroxyl-functional component (a2h) may comprise: 95 to 100 wt.%, of at least one polyol having 3 to 6 hydroxyl groups; and 0 to 5 wt.%, of at least one diol. In other specific examples, the hydroxyl-functional component (a2h) is substantially composed of or consists of at least one polyol having 3 to 6 hydroxyl groups. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0123] Suitable polyols having 3 to 6 hydroxyl groups may be saturated or unsaturated and may be aliphatic cycloaliphatic compounds: 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 tetrols and pentols include: 2,2-bis(hydroxymethyl)propane-1,3-diol (neopentetrol); pentose; pentopiperanose; 6-deoxyhepiperanose; 2,5-anhydrous hexitol; 1,5-anhydrous hexitol; 6-deoxyhexose; 1-deoxyhexitol; and pentitol. An exemplary polyol having six hydroxyl groups is D-glucanol (sorbitol). In specific examples, 2-ethyl-2-hydroxymethyl-1,3-propanediol (trimethylolpropane), 2,2-bis(hydroxymethyl)propane-1,3-diol (neopentetrol), or mixtures thereof may be used.

[0124] This disclosure does not exclude the use of (C2-C4) alkyl oxidants of the aforementioned diols, triols and higher polyols as reactants of polyols having 3 to 6 hydroxyl groups.

[0125] Suitable diols for use with hydroxyl-functionalized components may be saturated or unsaturated and may be aliphatic or cycloaliphatic dihydroxy compounds. The reactant diols typically have a molecular weight of 250 Daltons or less. When used herein, the term "diol" may include its equivalent ester-forming derivatives; however, the limitation is that the molecular weight requirement applies only to diols and not to their derivatives. Exemplary ester-forming derivatives include acetates of diols and, for example, ethylene oxide or ethyl carbonate of ethylene glycol.

[0126] Typical diols are diols having 2 to 10 carbon atoms. Examples of such 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; cyclohexanediol; and polyoxyalkylene glycols, such as diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, and tetrapropylene glycol. Mixtures of these diols may be used.

[0127] Based on the weight of the carboxyl functional component, the carboxyl functional component (a2c) may comprise: 75 to 100 wt.%, such as 80 to 100 wt.% or 90 to 100 wt.% of at least one dicarboxylic acid; and 0 to 25 wt.%, such as 0 to 20 wt.% or 0 to 10 wt.% of at least one monocarboxylic acid. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0128] The dicarboxylic acids used herein include aliphatic and / or cyclic aliphatic dicarboxylic acids. Dicarboxylic acids typically have a molecular weight of less than 600 Daltons. As used herein, the term "dicarboxylic acid" includes equivalents of dicarboxylic acids having two functional carboxyl groups that behave substantially similarly to dicarboxylic acids when reacting with polyols to form polyesters. These equivalents include esters and ester-forming reactive derivatives, such as amides and anhydrides, however the limitation is that the molecular weight ranges mentioned above relate to acids and not to their equivalent esters or ester-forming derivatives. Thus, this includes esters of dicarboxylic acids with a molecular weight greater than 300 Daltons or acid equivalents of dicarboxylic acids with a molecular weight greater than 300 Daltons, limited by the limitation that the molecular weight of the acid is less than 300 Daltons. Additionally, dicarboxylic acids may contain any one or more substituents or combinations thereof that do not substantially interfere with polymer formation and the use of the polymers disclosed herein.

[0129] Typical dicarboxylic acids include those selected from the following: 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 can be used.

[0130] Dimeric fatty acids can be used as dicarboxylic acid reactants in the polyester synthesis reactions described above. Exemplary dimer fatty acids include C36 to C44 aliphatic diacids that can be prepared by oxidative coupling of C18 to C22 unsaturated monoacids. Dimeric acids obtained by oxidative coupling of oleic acid, linoleic acid, or rosin oil fatty acids can be used. However, in specific examples where at least one dimer fatty acid is used in the reaction, at least one non-dimerized dicarboxylic acid is typically present. More specifically, in the case of using at least one dimer fatty acid, the dimer fatty acid can be reacted in amounts of 5 to 50 wt.% (typically 5 to 40 wt.%, 5 to 30 wt.%, or 5 to 25 wt.%) based on the total weight of the carboxyl functional component. In various non-limiting examples, it is explicitly considered that all values ​​and ranges (both whole and fractional, including those described above and those between those described above) are used herein.

[0131] Monocarboxylic acids suitable reactants in polycondensation reactions include aliphatic and / or cyclic aliphatic monocarboxylic acids. These monocarboxylic acids typically have a molecular weight of less than 300 Daltons. Exemplary monocarboxylic acids that can be used alone or in combination include: formic acid; acetic acid; propionic acid; n-butyric acid; isobutyric acid; 2-ethylhexanoic acid; octanoic acid; isononanoic acid; decanoic acid; dodecanoic acid; tetradecanoic acid; palmitic acid; and stearic acid.

[0132] The (cyclic) aliphatic hydroxycarboxylic acid component (a2hc) may participate in the polycondensation reaction to produce a non-aromatic polyester polyol (a2) as needed. In its presence, the total amount of hydroxycarboxylic acid is typically up to 10 wt.% 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. Corresponding lactones may also be used in place of monohydroxycarboxylic acids as reactants.

[0133] Typically, the reaction mixture provided for the aforementioned polycondensation reaction is substantially solvent-free. Furthermore, the initial reaction mixture may be substantially free of added water. However, if the reaction is carried out in solution, a suitable solvent may be a non-reactive, substantially anhydrous organic liquid capable of dissolving at least 1 wt.% and typically more than 10 wt.% of the polyester product at 25°C. Suitable organic solvents that can be used alone or in combination include: aromatic hydrocarbons, such as toluene and xylene; aliphatic hydrocarbons, such as heptane and decane; alicyclic hydrocarbons, such as cyclohexane and decahydronaphthalene; chlorinated hydrocarbons, such as chloroform and trichloroethylene; esters, such as ethyl acetate and methyl butyrate; and ethers, such as tetrahydrofuran (THF) and dimethyl ether.

[0134] Polycondensation reactions can be carried out in the presence of a suitable catalyst. Common catalysts include acid catalysts and organometallic catalysts, with titanium, zirconium, and tin alkoxides, carboxylates, and chelates being examples of the latter. Typically, the catalyst is a titanium alkoxide, titanium carboxylate, or titanium chelate catalyst.

[0135] Exemplary titanium alkoxides include: tetramethyl titanate; tetraethyl titanate; tetrapropyl titanate; tetraisopropyl titanate; tetrabutyl titanate; tetrapentyl titanate; tetrahexyl titanate; tetra-octyl titanate; tetranonyl titanate; tetra(dodecyl) titanate; tetra(hexadecyl) titanate; tetra-octadecyl titanate; tetratetradecyl titanate; tetraheptyl titanate; and mixtures thereof. The tin or zirconium counterparts of the above alkoxides may be partially substituted as catalysts.

[0136] Typically, the amount of catalyst used is 0.1 to 5 wt.%, for example, 0.1 to 2.0 wt.%, 0.1 to 1.5 wt.%, or 0.1 to 1.0 wt.%, based on the total weight of the reactants (a2h, a2c, and a2hc). In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0137] Polycondensation reactions can also be carried out in the presence of at least one stabilizer. Based on the total weight of the reactants (a2h, a2c and a2hc), typical stabilizers commonly present in amounts from 0.01 to 5 wt.% may be: hydroquinone and its alkylated derivatives; phenolic compounds having electron-withdrawing substituents; and quinone-type compounds. Specific examples of such stable 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-tertiary butylcatechol; 4-methoxyphenol; methylhydroquinone; 4-chloro-2-nitrophenol; 2,4-dinitro-p-cresol; 2,4-dinitrophenol; and phenanthrene.

[0138] In the case of a stabilizer used in the polycondensation reaction, one or more known electron donors that form an electron-donor-acceptor complex may be further added to the mixture of reactants. Based on the total weight of the reactants (a2h, a2c, and a2hc), these electron donors, conventionally comprising a total of 0.01 to 1 wt.%, include: 1-methylimidazole; 2-methylimidazole; 2-ethyl-4-methylimidazole; 2-heptadecylimidazole; 2-isopropylimidazole; 2-(2-ethyl-4-methylimidazolyl)-1-cyanoethane; and 2-undecylimidazole. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0139] In the synthesis of polyesters, the reactants, catalysts, and any stabilizers and electron donors are typically loaded into a suitable reaction vessel equipped with distillation equipment. This vessel is typically dried and purged with an inert gas (such as nitrogen or argon) before loading, and an inert atmosphere is maintained within the vessel during the reaction. The vessel temperature is typically set based on the lowest boiling point of the reactant (commonly an alcohol). In various specific examples, temperatures of about 125 to about 300°C or about 125 to about 275°C can be considered standard. For the initial duration, the vessel can be kept at atmospheric pressure, but once water distillation is no longer observed, at least a partial vacuum can be applied to the vessel to drive the polycondensation reaction to completion.

[0140] The reaction can be monitored by analyzing the acid value (Av) of the reactant mixture over time, and the reaction typically stops when the measured acid value is less than about 10 mg KOH / g, or typically 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, catalyst type, and reactants used: however, it will generally be about 0.5 to about 20 hours, for example about 1 to about 8 hours or about 2 to about 6 hours. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0141] Polyesters synthesized by polycondensation reactions can be separated and purified using methods known in the art, including filtration, extraction, evaporation, distillation, or chromatography. (a3) ​​Another (meth)acrylate copolymer

[0142] In some specific examples, the binder portion a) of the composition may further comprise: (a3) ​​at least one (meth)acrylate copolymer having an active hydrogen group, which is different from the hydroxyl-functional (meth)acrylate polymer of component (a1), wherein the (meth)acrylate copolymer (a3) ​​has a water solubility of less than about 6 g / 100 ml water at about 20°C.

[0143] This supplemental or co-adhesive (meth)acrylate component (a3) ​​will typically be a small amount of the adhesive portion a). For example, in some specific instances, the amount of (meth)acrylate copolymer (a3) ​​present in the adhesive portion a) based on the weight of the adhesive portion a) may be 0 to 20 wt.%. In some specific instances, the (meth)acrylate copolymer (a3) ​​may be present in portion a) in fractional amounts relative to its component (a1), such as 0 to 20 wt.%, 0 to 10 wt.%, or 1 to 5 wt.%. In various non-limiting specific instances, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0144] In addition to being water-insoluble, the (meth)acrylate copolymer of component (a3) ​​may not be water-dispersible. For example, copolymers typically do not form stable dispersions in water, and therefore, when stored at 40°C for 4 weeks, the dispersion will show sedimentation or phase separation. Including such copolymers often increases the hydrophobicity of waterborne coating compositions, which can be used to improve their applicability and the erosion and weather resistance of coatings obtained from them.

[0145] In some specific examples, the (meth)acrylate polymer of component (a3) ​​has: a calculated hydroxyl value of about 100 to about 600 mg KOH / g; an acid value of about 0 to about 35 mg KOH / g; and a number average molecular weight of about 1000 to about 4000 Daltons. In other specific examples, the (meth)acrylate polymer of component (a3) ​​has: a calculated hydroxyl value of about 100 to about 300 mg KOH / g, such as about 100 to 200 mg KOH / g; an acid value of about 0 to about 30 mg KOH / g, such as 10 to 30 mg KOH / g; and a number average molecular weight of about 1000 to about 4000 Daltons. Within the binder portion a), the co-binder component (a3) ​​may be further exemplified as having a particle size of about 60 to about 200 nm, as determined by laser diffraction. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0146] Hydroxyl-functional (meth)acrylic acid copolymers (a3) ​​are commercially available or can be produced as described above. The olefinic unsaturated monomers copolymerized therein can be selected according to type and amount so that the copolymer obtains the desired molecular weight, acid value and hydroxyl value. The synthesis of (meth)acrylic acid copolymer B, an example of US2012237688A1 (Huybrechts et al.), is utilized herein, and this reference is expressly incorporated herein by reference in its entirety in various non-limiting specific examples. (a4), (a5) Non-polymerizable polyols

[0147] Adding a specific nonpolymeric low molecular weight polyol to part a) of the composition can improve the moisture resistance of the coating obtained from the composition and promote easier mixing between the two parts of the composition. Any improvement in such mixing can translate into better suitability of the coating composition and an improved appearance of the coating obtained therefrom.

[0148] In one specific example, the binder portion a) of the two-part (2K) composition may further comprise: (a4) at least one nonpolymeric acyclic polyol having a weight-average molecular weight (Mw) of less than about 300 Daltons and a water solubility of less than about 6 g / 100 ml water at about 20°C. For example, based on the weight of the binder portion a), the amount of (a4) at least one nonpolymeric acyclic polyol in the binder portion a) may be 0 to 10 wt.%. In some specific examples, (a4) at least one nonpolymeric acyclic polyol may be present in the binder portion a) in fractional amounts relative to its component (a1). For example, based on the weight of component (a1), the binder portion a) may comprise 0 to 10 wt.%, 0 to 8 wt.%, 0 to 5 wt.%, or 0 to 3 wt.% of (a4) at least one nonpolymeric acyclic polyol. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0149] Exemplary nonpolymeric acyclic polyols that can be used alone or in combination include: 2-ethylhexane-1,3-diol; and 2-butyl-2-ethyl-1,3-propanediol.

[0150] In another specific example, which is not mutually exclusive with the specific examples given above, the binder portion a) of the two-part (2K) composition may further comprise: (a5) at least one non-polymeric cyclic aliphatic polyol having a weight-average molecular weight (Mw) of less than about 300 Daltons. For example, based on the weight of the binder portion a), the amount of (a5) at least one non-polymeric cyclic aliphatic polyol in the binder portion a) may be 0 to 10 wt.%. In some specific examples, (a5) at least one non-polymeric cyclic aliphatic polyol may be present in the binder portion a) in fractional amounts relative to its component (a1). For example, based on the weight of component (a1), the binder portion a) may comprise 0 to 10 wt.%, 0 to 8 wt.%, 0 to 5 wt.%, or 0 to 3 wt.% of (a5) at least one non-polymeric cyclic aliphatic polyol. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0151] Exemplary nonpolymeric cycloaliphatic polyols that can be used alone or in combination include: 1,4-cyclohexanediethanol; 1,3-cyclohexanediethanol; 1,2-cyclohexanediethanol; 1,4-cyclohexanediethanol; 2,2-bis(4-hydroxycyclohexyl)propane; disohydro-D-glucanol (isosorbitol); and 4,8-bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane. In a specific example, at least one nonpolymeric cycloaliphatic polyol comprises 1,4-cyclohexanediethanol. Part b) Crosslinking agent

[0152] The crosslinking agent portion b) of the composition of the present invention comprises at least one polyisocyanate compound having a -NCO side group. It is not excluded that the crosslinking agent portion b) of the composition may comprise other crosslinking compounds besides polyisocyanate compounds having a -NCO side group, such as melamine resin and end-capped isocyanates.

[0153] The molar ratio of active hydrogen atoms to -NCO groups in the two-part (2K) composition 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, for example, be from about 2:1 to about 1:2 or from about 1.5:1 to about 1:1.5. The term "-NCO group" includes capped -NCO groups and is therefore included in the molar ratio terminology. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0154] As used herein, "polyisocyanate" means a compound containing at least two -N=C=O functional groups, such as 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.

[0155] Aliphatic and cycloaliphatic polyisocyanates may contain 6 to 100 carbon atoms, which are linearly linked or cyclized and have at least two isocyanate reactive groups. Examples of suitable aliphatic isocyanates include linear isocyanates such as ethyl diisocyanate, trimethyl diisocyanate, butyl diisocyanate, tetramethyl diisocyanate, 1,6-hexamethylene diisocyanate (HDI), octyl diisocyanate, nonyl diisocyanate, decyl diisocyanate, nonane triisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, bis(ethyl isocyanate) carbonate, and bis(ethyl isocyanate) ether. Exemplary cycloaliphatic polyisocyanates include dicyclohexylmethane 4,4'-diisocyanate (H12MDI), 1-isocyanomethyl-3-isocyano-1,5,5-trimethyl-cyclohexane (isophorone diisocyanate, IPDI), cyclohexane 1,4-diisocyanate, hydrogenated phenyl dimethyl diisocyanate (H6XDI), 1-methyl-2,4-diisocyano-cyclohexane, m- or p-tetramethylxylene diisocyanate (m-TMXDI, p-TMXDI), and dimer fatty acid diisocyanates. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0156] The term "aromatic polyisocyanate" is used herein to describe an organoisocyanate in which the isocyanate group is directly linked to a ring of a mononuclear or polynuclear aromatic hydrocarbon group. A mononuclear or polynuclear aromatic hydrocarbon group also means a substantially planar cyclic hydrocarbon portion of a conjugated double bond, which may be a single ring or may include multiple condensed (fused) or covalently linked rings. The term aromatic also includes alkylaryl groups. Typically, the hydrocarbon (main) chain comprises 5, 6, 7, or 8 main chain atoms in a ring. Examples of such planar cyclic hydrocarbon moieties include cyclopentadienyl, phenyl, naphthyl-,

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

[12] annulenyl-, [8]annulenyl-, perinaphthene, 1,9-dihydropyrene, and (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.

[0157] Exemplary aromatic polyisocyanates include: all isomers of toluene diisocyanate (TDI), in pure isomeric form or in mixtures of several isomers; naphthalene 1,5-diisocyanate; diphenylmethane 4,4'-diisocyanate. 4,4'-diisocyanate (MDI); diphenylmethane 2,4'-diisocyanate and mixtures of diphenylmethane 4,4'-diisocyanate and its 2,4' isomers, or mixtures thereof with higher-functionality oligomers (so-called crude MDI); phenyl dimethyl diisocyanate (XDI); diphenyl-dimethylmethane 4,4'-diisocyanate; dialkyl and tetraalkyl-diphenylmethane diisocyanate; diphenylmethyl 4,4'-diisocyanate; phenyl 1,3-diisocyanate; phenyl 1,4-diisocyanate; triphenylmethane triisocyanate, 1,3,5-phenyltriisocyanate; and 2,4,6-toluene triisocyanate.

[0158] The polyisocyanates may have been biureted, ureocarboxylated and / or isocyanurized by commonly known methods before use. When used, these derivatives may be substantially free of parent diisocyanates: these derivatives may have been separated from any excess parent diisocyanates by conventional means (including but not limited to distillation).

[0159] It should also be noted that the term "polyisocyanate" includes hydrophilic prepolymers formed by partially reacting the aforementioned aliphatic, cycloaliphatic, aromatic and heterocyclic isocyanate polyether polyols or polyester polyols to obtain isocyanate functional oligomers, which can be used alone or in combination with free isocyanates.

[0160] The term "polyisocyanate" also includes ion-modified isocyanate functional compounds, such as ion-modified isocyanate functional prepolymers. Ion-modified polyisocyanates contain at least two isocyanate groups and at least one ion or ion-generating group. In some specific instances, the crosslinking agent portion b) may include anion-modified isocyanate functional compounds, such as anion-modified isocyanate functional prepolymers. Suitable anions or anion-generating groups in this regard include carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, and their salts. Suitable bases that can neutralize the anion groups to form such salts include: alkali metals, such as Na and K; ammonium; and trialkylamines, such as triethylamine and triisopropylamine.

[0161] Exemplary polyisocyanates available from Covestro AG and applicable to this 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. Additives and adjuvants.

[0162] The compositions disclosed herein may further include or exclude one or more adjuvants and additives that can impart improved properties to the compositions and coatings obtained therefrom. For example, such adjuvants and additives may impart one or more of the following: reduced darkness; improved image clarity (DOI); longer permissible processing time; faster curing time; lower residual tack; and improved leveling properties. Such adjuvants and additives include: catalysts; plasticizers; stabilizers, including UV stabilizers; reactive diluents; desiccants or dehumidifiers; adhesion promoters; wetting agents; defoamers; flame retardants; rheology control agents; colorants; dyes; effect pigments; cosolvents; and non-reactive diluents.

[0163] These adjuvants and additives may be used in the desired combination and proportions, subject to the limitation that they do not adversely affect the properties and essential characteristics of the composition. Although there may be exceptions in some cases, these adjuvants and additives typically constitute 0 to 40 wt.%, for example, 0 to 30 wt.%, of the total composition.

[0164] Generally, adjuvant materials and additives containing reactive groups can be incorporated into appropriate portions of the two-part (2K) composition to ensure its storage stability; non-reactive materials can be formulated into either or both of the two parts. For example, in some specific instances, the crosslinking agent portion b) of the composition may not contain compounds containing active hydrogen atoms.

[0165] 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 formic acid, such as stannous octoate, stannous oleate, stannous acetate, and stannous laurate; dialkyltin diformate, such as dibutyltin dilaurate and dibutyltin diacetate; tertiary amines; alkanolamine compounds; 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine; tetraalkylammonium hydroxide; alkali metal hydroxides; alkali metal alkoxides; tin alkoxides, such as dibutyltin dimethylethanol, dibutyltin diphenyloxide, and diisopropoxydibutyltin; tin oxides, such as dibutyltin oxide and dioctyltin oxide; reaction products of dibutyltin oxide with phthalates; tin thiolates; alkyl titanates; organoaluminum compounds, such as aluminum triacetate, aluminum triacetate, and aluminum ethylacetate diisopropoxy; chelates. Compounds such as zirconium tetraacetylpyruvate and titanium tetraacetylpyruvate; organosilicon titanium compounds; bismuth tris(2-ethylhexanoate); acid compounds such as phosphoric acid and p-toluenesulfonic acid; triphenylboron; triphenylphosphine; 1,8-diazabicycloundec-7-ene (DBU); 1,5-diazabicyclo[4.3.0]non-5-ene; 1,4-diazabicyclo[2.2.2]octane; 4-dimethylaminopyridine; 1,5,7-trizabicyclo[4.4.0]dec-5-ene; 7-methyl-1,5,7-trizabicyclo[4.4.0]dec-5-ene; 1,8-bis(tetramethylguanidine)naphthalene; and 2-tert-butyl-1,1,3,3-tetramethylguanidine.

[0166] Depending on the nature of the isocyanate, the amount of catalyst used is typically 0.005 to 2 wt% of the composition. For example, based on the weight of the composition, the composition may contain 0.01 to 2 wt.% or 0.01 to 1 wt.% of catalyst. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0167] The addition of certain additives can promote adhesion of the coating composition to a specific substrate. In this regard, based on the weight of the composition, the composition may contain 0 to 5 wt.%, for example 0.5 to 5 wt.%, of at least one additive selected from the following: morin (2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-coumarone-4-one); 3,7-dihydroxy-2-naphthoic acid (3,7-dihydroxynaphthoic acid); gallophenolic acid (2,3,4-trihydroxybenzoic acid); 3,4-dihydroxy-benzoguanidine-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-hydroxypropyl-1,2,3-tricarboxylic acid); and mixtures thereof. In certain specific instances, citric acid, gallic acid, or para-aminosalicylic acid (PAS) may be used alone or in combination.

[0168] The term “pigment” is used herein to refer to a molecule that is insoluble in a liquid carrier and imparts color or optical effects to it.

[0169] In some specific instances, the composition may contain at least one colored pigment. The colored pigments effective herein may be organic or inorganic. Exemplary colored pigments that can be used alone or in combination include: azo pigments; anthraquinone pigments; benzimidazolone pigments; isoindoline pigments; naphthol pigments, such as naphthol red. (red); nitroso pigments; perinone pigments; perylene pigments; polycyclic pigments; pyrrolopyrrole pigments; phthalocyanine, such as copper phthalocyanine blue and copper phthalocyanine green; quinacridone, such as quinacridone violet; quinoline yellow pigment; dichlorophenate pigment; carbon black; azurite; aluminum silicate; potassium aluminum silicate; antimony oxide; barium metaborate; barium sulfate; cadmium sulfide; cadmium selenide; calcium carbonate; calcium metaborate; calcium metasilate; chromium oxide; clay; copper oxide; copper oxychloride; feldspar; iron oxide, such as yellow and red iron oxide; kaolinite; zinc barium white; magnesium silicate; nepheline syenite; silicates; sulfides; talc; titanium dioxide; ultramarine; zinc chromate; zinc oxide; and zinc phosphate.

[0170] In certain specific examples, the composition may contain at least one effect pigment, meaning a pigment that exhibits an optical effect not caused by absorption. Specific examples include graphite effect pigments, metallic 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 / g, for example about 5 to about 50 m² / g, as determined by nitrogen absorption according to the Brunauer-Emmett-Teller (BET) method; and an average volumetric particle size (Dv50) of about 1 to about 500 μm, for example about 5 to about 100 μm, as determined by laser diffraction. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0171] Metallic effect pigments may include needle-shaped, spherical, ellipsoidal, cylindrical, bead-shaped, cubic, flake-shaped, or plate-shaped particles. Different shaped particles may be used alone or in combination.

[0172] Exemplary metals that may be included in 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 constituent 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 the pigment, the thickness of such metal oxide layers will typically be 20 to 400 nm, such as 50 to 400 nm or 50 to 250 nm. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0173] Pearlescent pigments comprise a transparent, non-metallic flake-shaped substrate coated with at least one layer comprising a metal oxide having a refractive index. In some specific examples, multiple metal oxide layers are used, wherein the refractive indices of adjacent layers differ by at least about 0.1. In some specific examples, the pearlescent pigment exhibits interference colors when viewed against a black background.

[0174] Exemplary non-metallic sheet substrates include: natural mica; synthetic mica; bismuth oxychloride; graphite; alumina; mica iron oxide; perlite; silica; borosilicate glass; glass; mica coated with titanium dioxide; and mica coated with iron oxide.

[0175] Exemplary metal oxides that can form one or more coatings of pearlescent pigments 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 can be determined independently, but it is conventionally known to be about 20 to about 400 nm, such as 50 to 400 nm or 50 to 250 nm. In various non-limiting specific examples, it is explicitly considered that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those set forth above) are used herein.

[0176] The rheology control agent used in the compositions of the present invention may, as needed, comprise fillers, thickeners, and combinations thereof. The total amount of rheology control agent in the composition typically does not exceed 10 wt.% based on the weight of the composition. Based on the weight of the composition, the composition may contain, for example, 0 to 8 wt.%, 0 to 5 wt.%, or 0 to 2 wt.% of rheology control agent. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0177] Exemplary thickeners include: clay-based thickeners, such as organoclay; polysaccharides, such as guar gum and saffron gum; polyacrylates; and associative thickeners. Particularly noteworthy are the use of cellulose or cellulose derivatives such as the following as polysaccharide thickeners: carboxymethyl cellulose; methyl cellulose; hydroxyethyl cellulose; hydroxyethyl methyl cellulose; hydroxypropyl methyl cellulose; cellulose nanofibers; and cellulose nanocrystals.

[0178] The filler may include needle-like, spherical, ellipsoidal, cylindrical, bead-like, cubic, or flake-like particles, which may be used alone or in combination. Furthermore, it is envisioned that aggregates of more than one particle type may be used. The filler typically has an average volumetric particle size (Dv50) of about 0.1 to about 1500 μm, for example, about 1 to about 1250 μm, as measured by laser diffraction. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0179] Exemplary fillers include calcium carbonate, calcium oxide, calcium hydroxide (lime powder), precipitated and / or pyrolytic 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 minerals. Organic fillers may also be used, specifically wood fiber, wood flour, sawdust, cellulose, cotton, pulp, cotton, wood chips, shredded straw, rice husks, ground walnut shells, and other shredded fibers. Short fibers, such as glass fiber, glass filament, polyacrylonitrile, carbon fiber, Kevlar fiber, or polyethylene fiber, may also be added.

[0180] When present, pyrolytic and / or precipitated silica may have a BET specific surface area of ​​about 10 to about 90 m² / g. When used, such silica may not cause any additional increase in the viscosity of the composition, but may help to strengthen the cured composition. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0181] It is also conceivable to use pyrolytic and / or precipitated silica with a high BET specific surface area (advantageously about 100 to about 250 m2 / g) as a filler: because the larger the BET surface area, the smaller the weight ratio of silica can be used to achieve the effect of strengthening the cured composition. In various non-limiting specific examples, it is explicitly considered that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) are used herein.

[0182] Hollow spheres with a mineral or plastic outer shell may also be used. These hollow spheres may be, for example, commercially available hollow glass spheres under the trademark Glass Bubbles®. Plastic-based hollow spheres, such as Expancel® or Dualite®, may also be used. For example, they may comprise inorganic or organic materials, each having an average volumetric particle size (Dv50) of 1 mm or less, typically 500 µm or less, as determined by laser diffraction.

[0183] Fillers that impart hygroscopic properties to the composition are typical for many applications. Such fillers are also described as rheology adjuvants and include, for example, hydrogenated castor oil, fatty acid amides, and expandable plastics such as PVC.

[0184] For the purposes of this disclosure, "plasticizer" is a substance that reduces the viscosity of a composition and thus promotes its processability. In this document, the plasticizer may comprise up to 10 wt.% or up to 5 wt.% of the total weight of the composition, and is typically selected from: ethyl diaminocarbamate; ethers of monofunctional, linear, or branched C4-C16 alcohols, such as Cetiol OE (available from BASF); esters of rosin 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 fatty acids with OH- groups or epoxidized groups; glycolates; benzoates; phosphate esters; sulfonates; trimellitates; polyether plasticizers, such as terminally capped polyethylene glycol or polypropylene glycol; polystyrene; hydrocarbon plasticizers; chlorinated paraffins; and mixtures thereof. It should be noted that, in principle, phthalates can be used as plasticizers, but these esters are not typical due to their toxicological potential.

[0185] For the purposes of this invention, "stabilizer" should be understood as an antioxidant, heat stabilizer, or hydrolytic stabilizer. Based on the total weight of the composition, the stabilizer may comprise a total of up to 10 wt.% or up to 5 wt.%. Standard commercially available examples of stabilizers suitable for use herein include: hindered phenols; thioethers; benzotriazoles; benzophenone; benzoate esters; cyanoacrylates; acrylates; amines of the hindered amine light stabilizer (HALS) type; phosphorus; sulfur; and mixtures thereof.

[0186] To further increase storage life, it is generally reasonable to further stabilize the disclosed compositions in terms of moisture penetration by using a desiccant. Examples of suitable desiccants or dehumidifiers include: silicone; anhydrous calcium sulfate (gypsum); calcium sulfate dihydrate (gypsum); calcium oxide; microcrystalline kaolinite clay; molecular sieves, such as molecular sieves including natural or synthetic zeolites; and activated alumina.

[0187] The waxes effective in this disclosure may have a softening point of about 50 to about 150°C and may include one or more of the following: polyethylene having a number average molecular weight (Mn) of about 500 to about 7500; petroleum waxes, such as paraffin and microcrystalline waxes; synthetic waxes prepared by polymerizing carbon monoxide with hydrogen, such as Fischer-Tropsch wax; polyolefin waxes, including functionalized polyolefin waxes, of which maleic diacid polyethylene, maleic diacid polypropylene and maleic diacid poly(ethylene-co-propylene) may be mentioned as examples; and hydrogenated animal oils, fish oils or vegetable oils. In various non-limiting specific examples, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those set forth above) be used herein.

[0188] Sometimes it is also necessary to reduce the viscosity of the compositions according to this disclosure for specific applications by using reactive diluents. The total amount of reactive diluent present, based on the total weight of the composition, will typically be 0 to 10 wt.%, for example, 0 to 5 wt.%. In various non-limiting specific examples, it is explicitly considered that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) are used herein.

[0189] The presence of co-solvents and non-reactive diluents in the compositions disclosed herein is also not excluded, as this can effectively adjust their viscosity. For example, but only for illustration, the compositions 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; diesters, such as dimethyl succinate, dimethyl glutarate, and dimethyl adipate; and (di)alkyl carbonate solvents, such as ethylene carbonate, propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (diethyl... Carbonate; DEC); ethers, such as tetrahydrofuran, dialkyl 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, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-butyl ether, propylene glycol butyl ether, propylene glycol phenyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol di Dimethyl ether and dipropylene glycol di-n-butyl ether; acetamide solvents such as dimethyl acetamide and N-methylpyrrolidone; ketone solvents such as acetone, diisobutyl ketone, isobutylheptyl ketone, isophorone, methyl ethyl ketone, methyl n-pentyl ketone and methyl isobutyl ketone; toluene; xylene; diphenylmethane; diisopropylnaphthalene; petroleum fractions such as Solvesso® products (available from Exxon); and chlorinated solvents such as 4-chlorotrifluoromethylbenzene and 3,4-bis(dichloro)trifluoromethylbenzene.

[0190] Any co-solvent or non-reactive diluent in the two-part (2K) composition does not need to be added independently to any one or more components or the composition itself. Alternatively, one or more components of the composition may be provided in the co-solvent or diluent. In certain specific instances, any solvent or diluent included in the crosslinking agent portion b) of the composition may be free of active hydrogen atoms.

[0191] Typically, based on the total weight of the composition, the co-solvent and non-reactive diluent together account for less than 5 wt.%, particularly less than 1 wt.%, at least partially excluding such co-solvent and non-reactive diluent so that the two-part (2K) aqueous composition can have a volatile organic compound (VOC) content of up to about 420 g / l (e.g., up to about 360 g / l, such as up to about 300 g / l or even up to about 240 g / l) as measured according to ISO 11890-2:2006. In various non-limiting specific examples, it is explicitly considered that all values ​​and ranges (both whole and fractional, including those set forth above and those between those set forth above) are used herein. Methods and Applications

[0192] For a two-part (2K) curable composition, the reactive portions are combined and mixed in such a manner to induce curing. The reactive compounds can be mixed under sufficient shear force to produce a homogeneous mixture. This can be achieved without special conditions or equipment. That is, suitable mixing apparatus may include: static mixing apparatus; magnetic stirring rod apparatus; wire stirring apparatus; auger; batch mixer; planetary mixer; CW Brabender or Banburry® type mixer; and high-shear mixers, such as blade blenders and impeller mixers. In some specific instances, once the reactive portions are mixed, one or more of water, co-solvent, and non-reactive diluent may be added during mixing to adjust the viscosity of the composition.

[0193] For small applications using volumes less than 2 liters, a typical package for a two-part (2K) composition will be a side-by-side dual-canister or coaxial canister, wherein two tubular chambers are arranged side-by-side or internally to each other and sealed with pistons: the driving of these pistons allows the portions to be advantageously extruded from the canisters via a tightly fitted static or dynamic mixer. For larger volume applications, the two portions of the composition can be advantageously stored in canisters or drums: in this case, the two portions are extruded via a hydraulic press, specifically by means of a follower plate, and supplied via piping to a mixing device that ensures fine and highly uniform mixing of the hardener and binder portions. The binder portion is typically sealed with an airtight and moisture-proof seal, allowing the two portions to be stored for extended periods, ideally 12 months or longer.

[0194] Non-limiting examples of the two-part allocation apparatus and methods applicable to this disclosure include the apparatus and methods described in U.S. Patent Nos. 6,129,244 and 8,313,006, each of which is expressly incorporated herein by reference in its entirety in various non-limiting specific examples.

[0195] More typically, the composition described above is applied to the desired surface and then cured in situ. It is generally reasonable to pretreat the relevant surface to remove foreign matter before applying the composition. If applicable, this step can promote subsequent adhesion of the composition to such surfaces. Such treatments are known in the art and can be performed in a single-stage or multi-stage manner.

[0196] In some specific examples, the adhesion of the coating composition to the substrate surface can be promoted by applying a primer to the substrate surface that requires pretreatment. The primer composition may be necessary to ensure effective fixation and / or curing time of the adhesive composition on an inactive substrate.

[0197] It is not excluded that other intermediate layers may be provided between the primer and coating composition disclosed herein, as will be described below in relation to multilayer coatings.

[0198] Typically, the composition is coated onto the desired surface of a substrate by conventional coating methods, such as: brush coating; roller coating; doctor blade coating; printing methods; and spraying methods, including but not limited to air atomization spraying, air-assisted spraying, airless spraying and high-volume low-pressure spraying.

[0199] The composition is applied to the surface with a wet film thickness of about 10 to about 500 μm. Applying a thinner layer within this range is more economical and provides the possibility of reduced harmful viscous cured areas. However, control must be exercised in applying thinner coatings or layers to avoid the formation of discontinuous cured films. In various non-limiting specific examples, all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) are explicitly considered to be used herein.

[0200] Curing of the coated composition is typically carried out at temperatures of about 20 to about 200°C, and typically about 20 to about 160°C. Suitable temperatures depend on the specific compound present and the desired curing rate, and can be determined, in individual cases, by a person skilled in the art using simple preliminary tests if necessary. For example, in vehicle production line applications, curing temperatures of about 80 to about 160°C or about 100 to about 140°C may be effective. Conversely, for repair applications, curing temperatures of about 20 to about 80°C or about 40 to about 60°C may be effective. For applications involving large vehicles and transport vehicles (such as trucks, buses, and railway vehicles), curing temperatures of about 20 to about 80°C may be utilized. Of course, curing at lower temperatures within the range mentioned above is advantageous because it avoids the requirement to substantially heat or cool the mixture at the normally present ambient temperature. However, where applicable, conventional means, including drying and microwave induction, can be used to raise the temperature of the mixture formed by the individual elements of the composition above the mixing temperature and / or coating temperature. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0201] This disclosure also provides an article comprising: a metal substrate; and a multilayer coating disposed on the metal substrate, wherein at least one layer of the multilayer coating comprises the curing composition described herein. While the use of the curing composition as a primer, such as a base coat or sealant, is not excluded, the curing coating composition is more suitable for use or as: solid color paint; solid color topcoat; and / or clear coat. For example, the curing coating composition can be used or used as a transparent clear coat.

[0202] Exemplary articles are shown in Figure 1 attached herein. The article (1) shown comprises: a metal substrate (10); and a multilayer coating (11) disposed on the metal substrate, wherein the multilayer coating (11) comprises: a primer layer (110) disposed on the metal substrate; a color paint layer (120) comprising a compound that imparts color and / or visual effect, wherein the color paint layer is disposed on the primer layer (110); and a clear varnish layer (130) comprising a cured product of the two-part (2K) composition described above and disposed on the color paint layer (120).

[0203] Typically, a primer layer (110) is applied to promote adhesion between the substrate surface and subsequent coatings. Furthermore, the primer coating can enhance the overall physical properties of the coating system, particularly its corrosion resistance and impact strength. Moreover, the primer coating can improve the overall appearance of the coating system by providing a smooth layer upon which subsequent layers can be applied.

[0204] The primer layer (110) is disposed on and in direct contact with the metal substrate (10) as depicted in FIG1. ​​However, it should be understood that one or more intermediate coatings may be disposed between the metal substrate and the primer layer (110). Conversion coatings are a representative example of such intermediate coatings. In this document, the term "conversion" refers to a treatment of the substrate surface that chemically transforms the surface material into a different material. Typically, the metal or alloy surface substrate is chemically treated to provide a tightly adhered conversion coating, which consists entirely or partially of a stable form of the substrate metal (e.g., an oxidized form). Such chemical conversion coatings can exhibit high corrosion resistance and provide strong adhesion affinity to the subsequent primer layer (110).

[0205] A single primer layer (110) is depicted in Figure 1 for illustrative purposes only. However, in certain specific instances, more than one primer layer (110) may be present. Regardless of whether the primer is applied in a single or multiple layer manner, the total thickness of the at least one primer layer may typically be from about 10 to about 200 micrometers, such as from about 10 to about 150 micrometers, from about 10 to about 75 micrometers, or from about 20 to about 75 micrometers. In various non-limiting specific instances, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) be used herein.

[0206] The paint layer (120) in Figure 1 contains a compound that imparts color and / or visual effect and is disposed on the primer layer (110). In the case where the primer has been applied in multiple layers, the paint layer is disposed on the top primer layer relative to the surface of the metal substrate (10).

[0207] A single paint layer (120) is depicted in Figure 1 for illustrative purposes only. However, in certain specific instances, more than one paint layer (120) may be present. The lowest of these paint layers may be placed on and in direct contact with the primer layer (110). Whether the paint is applied in a single layer or multiple layers, the total thickness of the at least one paint layer may typically be about 5 to about 100 micrometers, such as about 5 to about 50 micrometers, about 5 to about 40 micrometers, or about 5 to about 30 micrometers. In various non-limiting specific instances, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those described above and those between those described above) be used herein.

[0208] In Figure 1, a clear varnish layer (130) comprising the cured product of the two-part (2K) composition described above is disposed on a color varnish layer (120). In the case where the color varnish has been applied in multiple layers, the clear varnish layer (130) is disposed on the uppermost color varnish layer relative to the surface of the metal substrate (10). The clear varnish layer (130) typically has good chemical resistance, mechanical abrasion resistance, and weather resistance. In addition, the clear varnish layer (130) will have satisfactory optical properties, including transparency and gloss.

[0209] Similarly, a single clear coat layer (130) is depicted in Figure 1 for illustrative purposes only. However, in certain specific instances, more than one clear coat layer (130) may be present. The lowest of these clear coat layers may be placed on and in direct contact with the colored coat layer (120). 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 micrometers, such as from about 10 to about 200 micrometers, from about 20 to about 100 micrometers, or from about 30 to about 90 micrometers. In various non-limiting specific instances, it is explicitly intended that all values ​​and ranges of values ​​(both whole and fractional, including those described above and those between those described above) be used herein.

[0210] The or each transparent varnish layer (130) of the article may typically be at least substantially light-transmitting. Thus, for example, the or each transparent varnish layer may be at least about 85%, at least about 90%, or at least about 95% light-transmitting, as determined by transmittance (TR) measurement according to ASTM D1746 (2023).

[0211] Another exemplary article is shown in Figure 2 attached herein. The article (1) shown comprises: a metal substrate (20); and a multilayer coating (21) disposed on the metal substrate, wherein the multilayer coating (21) comprises: a primer layer (210) disposed on the metal substrate; a color paint layer (220) comprising a compound that imparts color and / or visual effect, wherein the color paint layer is disposed on the primer layer (210); a binder layer (225) disposed on the color paint layer (220); and a clear coat layer (230) comprising a cured product of the two-part (2K) composition described above and disposed on the binder layer (225).

[0212] A bonding layer (225) may be inserted between the paint layer (220) and the clear coat layer (230) and may enhance their adhesion. In consideration of this insertion, the bonding layer (225) may typically be substantially light-transmitting. Thus, for example, the bonding layer (225) may be at least about 85%, at least about 90%, or at least about 95% light-transmitting, as determined by transmittance (TR) measurements according to ASTM D1746 (2023). In various non-limiting specific examples, all values ​​and ranges of values ​​(both whole and fractional, including those set forth above and those between those set forth above) are explicitly considered to be used herein.

[0213] A single binder layer (225) is depicted in FIG2 for illustrative purposes only. However, in certain specific instances, more than one binder layer (225) may be present. In such specific instances, the bottommost binder layer may be disposed on and in direct contact with the paint layer (220); a clear coat layer (230) comprising the cured product of the two-part (2K) composition described above will be disposed on and in direct contact with the topmost binder layer (225). In specific instances, the total thickness of the at least one binder layer is less than the total thickness of the clear coat layer (230). Alternatively or additionally, the total thickness of the at least one binder layer may be about 1 to about 50 micrometers, such as about 1 to about 25 micrometers, about 5 to about 25 micrometers, or about 5 to about 20 micrometers. In various non-restrictive specific instances, it is explicitly considered that all values ​​and ranges of values ​​(both wholes and fractions, including those described above and those between those described above) are used in this text.

[0214] The process of forming a multilayer coating conventionally incorporates the following steps: i) providing a metal substrate; ii) applying a first layer of a first curable coating composition onto the metal substrate and in direct contact with the metal substrate; iii) at least partially curing the first layer; iv) applying a second layer of a second curable coating composition onto the at least partially cured first layer and in direct contact with the first layer; v) at least partially curing the second layer; vi) applying a third layer of a third curable coating composition onto the at least partially cured second layer and in direct contact with the second layer; and vii) at least partially curing the third layer. Steps vi) and vii) may be performed and repeated during the repetition process to place a fourth layer and other layers onto the metal substrate. As described above, with respect to the multilayer coating shown in Figures 1 and 2, the first, second, third, and other curable compositions provide: at least one primer layer; at least one color coat layer; at least one binder layer (optional); and at least one clear coat layer.

[0215] The metal substrate provided in step i) may typically be pretreated prior to step ii). Such pretreatment may include at least one of the following: 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 mentioned above.

[0216] Cleaning is used to remove foreign matter from the surface of a metal substrate. Cleaning processes are known in the art and can be performed in a single-stage or multi-stage manner, comprising, for example, the use of one or more of the following: etching with an acid suitable for the substrate and an oxidizing agent selected as needed; acoustic treatment; plasma treatment, including 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 rinsing with water, preferably with deionized or demineralized water. In the case of using an aqueous alkaline degreasing bath, any residual degreasing agent on the surface should typically be removed by rinsing the substrate surface with deionized or demineralized water.

[0217] Independent of cleaning the substrate, the surface of the metal substrate (10) can be polished. Polishing typically includes sanding, which can be performed using, for example, a track-fed sander with sandpaper of a predetermined grit. After surface polishing, the metal substrate can be cleaned as needed to remove any dust or any other dirt or contaminants acquired during the polishing operation.

[0218] As used in the described process, the term "at least partially cured" means that curing of the curable coating composition has been initiated and, for example, crosslinking of the components of the composition has begun. This term covers any amount of curing from the formation of a single crosslink to a fully crosslinked state when curing conditions are applied. The rate and mechanism of curing of the coating composition depend on various factors, including its components, the functional groups of the components, and the parameters of the curing conditions.

[0219] At least partial solidification of a given coating generally indicates curing or drying. However, drying and curing can be indicated in other ways, such as changes in the viscosity of the coating, increases in the temperature of the coating, and / or changes in the transparency / opacity of the coating.

[0220] Typically, steps iv) and vi) of the coating process described above are initiated only when the aforementioned layer, which is at least partially cured or partially dried, can substantially retain its shape upon exposure to environmental conditions. "Substantially retain its shape" means that at least about 50% by volume, and more usually at least about 80% by volume or about 90% by volume, of the at least partially cured or dried layer retains its shape without flowing or deforming after a period of 5 minutes of exposure to environmental conditions. In such cases, gravity typically may not substantially affect the shape of the at least partially cured or partially dried layer after exposure to environmental conditions.

[0221] The shape of a layer that is at least partially dried or at least partially cured can typically affect whether the layer substantially retains its shape. For example, when a layer that is at least partially cured or dried is rectangular or has another minimal shape, it may have greater resistance to deformation at lower curing levels or lower drying levels compared to a layer with a more complex shape.

[0222] In certain specific examples, the coating of each subsequent layer (step iv); step vi) is performed primarily while the layer is still "green" before at least partially cured layers have reached their final cured state. In these specific examples, the coating of these layers can be considered "wet-on-wet," so adjacent layers are bonded to each other at least physically and also chemically. For example, it is possible that components in the first and subsequent layers can be chemically crosslinked / cured along the coating line, an effect that can benefit the lifespan, durability, and appearance of the finished product. The difference between partial curing and final cured states lies in whether the partially cured layer can be further cured or crosslinked. This does not actually preclude functional groups from existing in the final cured state, but these groups may remain unreacted due to steric hindrance or other factors.

[0223] In the repetitive process mentioned above, the thickness, width, shape, and continuity of each layer can be selected independently, such that the preceding and subsequent layers may be the same or different from each other in one or more such respects. For example, a given subsequent layer may only contact a portion of the exposed surface of at least partially cured or dried preceding layer: depending on the desired shape of the coating, the subsequent layer may be selectively applied to that layer.

[0224] The following examples illustrate this disclosure and are not intended to limit the scope of this disclosure in any way. Examples

[0225] The following commercially available products were used in the examples below: CE10P: Cardura E10P; glycidyl neopentanoate, available from Hexion. BYK® 345: Silicone surfactant, available from Altana. BYK® 333: Silicone-containing surface additive, available from Altana. Tinuvin® 292: Hindered amine light stabilizer, available from BASF. Tinuvin® 1130: Hydroxyphenylbenzotriazole UV absorber, available from BASF. EmpolS: Fatty acid dimer, available from Henkel. 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 stated, all remaining compounds were available from Sigma Aldrich. RSE1: Refer to Synthesis Example 1

[0226] In a reactor equipped with a propeller-type stirrer, thermometer, condenser, and monomer / initiator feeding system, 385 g of CE10P and 75 g of ethoxypropanol were loaded and heated to approximately 150°C. After 2.5 hours, 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 while maintaining the contents at 150°C. After feeding, the reactor contents were held for 30 minutes.

[0227] Following this holding period, after 2.5 hours, 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, while the contents were maintained at 150°C. After this addition, the feed system was flushed with 58 g of ethoxypropanol. After the flushing step, the reactor contents were maintained at 150°C for 2 hours.

[0228] 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 approximately 70°C.

[0229] The measured properties of the obtained dispersion are as follows: solids content, 45.1 wt.%; viscosity, 4500 centipoise; acid value, 27.8 mg KOH / g; and pH, 8.0. When stability was visually determined, the obtained aqueous dispersion showed no sedimentation after 4 weeks of storage at 60°C.

[0230] If determined by gel permeation chromatography (GPC) according to the ASTM 3536 polystyrene calibration standard, the molecular weight of the synthesized copolymer is: a number average molecular weight (Mn) of 5300 Daltons; and a weight average molecular weight (Mw) of 32800 Daltons. RSE2: Refer to Synthesis Example 2

[0231] Following the process of Reference Synthesis Example 1 (RSE1) and increasing the initiator loading in both stages by 50%, while using the same loading for other materials, a dispersion of hydroxyl-functional (meth)acrylate copolymer with a lower molar mass was prepared.

[0232] If the molecular weight of the synthesized copolymer is determined by gel permeation chromatography (GPC) according to the ASTM 3536 polystyrene calibration standard, it is: a number average molecular weight (Mn) of 4200 Daltons and a weight average molecular weight (Mw) of 17556 Daltons.

[0233] When visually determining stability, the obtained aqueous dispersion showed sedimentation of less than 4 weeks when stored at 60°C. Due to insufficient stability, the synthesized copolymer was not further evaluated. SE1: Synthesis Example 1

[0234] In a reactor equipped with a propeller-type stirrer, thermometer, condenser, and monomer / initiator feeding system, 385 g of CE10P and 75 g of ethoxypropanol were loaded and heated to approximately 150°C. After 2.5 hours, a mixture of 103 g of hydroxyethyl methacrylate, 217 g of styrene, 136 g of acrylic acid, 250 g of isoborneol methacrylate, 18 g of dicumyl peroxide, 77 g of CE10P, and 88 g of ethoxypropanol was added to the reactor while maintaining the contents at 150°C. After feeding, the reactor contents were held for 30 minutes.

[0235] Following this holding period, after 2.5 hours, 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, while the contents were maintained at 150°C. After this addition, the feed system was flushed with 58 g of ethoxypropanol. After the flushing step, the reactor contents were maintained at 150°C for 2 hours.

[0236] The reactor contents were cooled to 100°C and 190 g of ethoxypropanol were distilled off. 52 g of dimethylaminoethanol (DMEA) was added to the contents, and the resulting polymer blend was then diluted with 1805 g of water preheated to approximately 70°C.

[0237] The measured properties of the obtained dispersion are as follows: solids content, 45.1 wt.%; viscosity, 3800 centipoise; acid value, 27.8 mg KOH / g; and pH, 7.8. When stability was visually determined, the obtained aqueous dispersion showed no sedimentation after 4 weeks of storage at 60°C.

[0238] The molecular weight of the synthesized copolymer, determined by gel permeation chromatography (GPC) according to the ASTM 3536 polystyrene calibration standard, is: a number average molecular weight (Mn) of 4300 Daltons and a weight average molecular weight (Mw) of 16600 Daltons. Synthesis Example 2: Preparation of a solution of polyester polyol (PE1).

[0239] A mixture of 911 g of trimethylolpropane, 748 g of hexahydrophthalic anhydride, and 138 g of dimer fatty acid (EmpolS) 1008 from Henkel was heated to 250°C. Esterification was carried out by water separation until an acid value of less than 5 mg KOH / g was obtained. After cooling the reaction mixture to below 125°C, the solids content was adjusted to 70 wt.% with 90 g of xylene and 641 g of methoxypropyl acetate.

[0240] The obtained polyester polyol has a calculated hydroxyl value of 345 mg KOH / g and an acid value of 4.5 mg KOH / g. The calculated hydroxyl functionality is 5.6, and the calculated number average molecular weight (Mn) is 920 Daltons, as determined by gel permeation chromatography (GPC) according to the polystyrene calibration standard of ASTM 3536. Example 1

[0241] Two-part (2K) transparent coating compositions were prepared using the dispersions (RSE1, SE1, PE1) described above. Part a) of the two-part composition was obtained by mixing the components given in Table 1 below. Similarly, part b) of the two-part composition was obtained by incorporating Desmodur® N 3900 and ethylene glycol butyl ether acetate in the indicated amounts. The table details the preparation of the following: four reference coating compositions (RCC1 to RCC4); and two coating compositions (CC1 to CC2) according to this disclosure. Table 1 Element RCC1 (parts by weight) RCC2 (parts by weight) RCC3 (parts by weight) RCC4 (parts by weight) CC1 (parts by weight) CC2 (parts by weight) Part a) Acrylic copolymer dispersion (RSE1) 92.27 82.40 82.15 Acrylic copolymer dispersion (SE1) 92.27 82.40 82.15 Polyester Example B 5.47 5.45 5.47 5.45 2-Ethylhexane-1,3-diol 2.02 2.02 Propylene glycol methyl ether 1.31 1.31 1.01 1.31 1.01 1.31 Ethylene glycol butyl ether acetate 0.51 0.51 0.51 0.50 0.51 0.50 Mineral oil 1.62 1.62 1.62 1.61 1.62 1.61 N,N-Dimethylethanolamine 0.00 0.00 0.14 0.14 0.14 0.14 Deionized water 2.02 2.02 6.58 4.54 6.58 4.54 Byk 345 0.58 0.58 0.58 0.58 0.58 0.58 Byk 333 0.19 0.19 0.19 0.19 0.19 0.19 Tinuvin 292 0.66 0.66 0.66 0.66 0.66 0.66 Tinuvin 1130 0.85 0.85 0.85 0.85 0.85 0.85 Total weight of part a) 100.00 100.00 100.00 100.00 100.00 100.00 Part b) Desmodur® N 3900 47.3 47.3 47.3 47.3 47.3 47.3 Bayhydur XP2655 23.8 23.8 23.8 23.8 23.8 23.8 Ethylene glycol butyl ether acetate 23.7 23.7 23.7 23.7 23.7 23.7 Mineral oil 5.2 5.2 5.2 5.2 5.2 5.2 Total weight of part b) 100.0 100.0 100.0 100.0 100.0 100.0

[0242] The individual portions a) and b) given above were mixed in a weight ratio of 100:35 (a:b) to form coating compositions (RCC1-4, CC1 to CC2), with a molar ratio of active hydrogen atoms to -NCO groups (OH / NCO in this document) of 0.7:1 to 1.4:1 for each composition. The viscosity of each composition was adjusted to 20 to 28 centipoise using deionized water, as measured at room temperature using a Brookfield CAP2000 viscometer (400 rpm, No. 4 spindle). The resulting transparent varnish compositions were sprayed onto black coated steel plates and baked at 60°C for 30 minutes. The obtained coatings were then subjected to the following evaluation tests, and the results are provided in Table 2 below.

[0243] Wave-Scan: Wave scanning was performed using the Wavescan-DOI available from BYK-Gardner, designed to simulate visual perception. The instrument provides a laser point source that illuminates the sample at a 60° angle: the relevant detectors measure the intensity of reflected light at equal but relative angles. Long-wavelength signals (structure size > 0.6 mm) and short-wavelength signals (structure size < 0.6 mm) are separated from the measured signals using a mathematical filtering function. The instrument is rolled across the surface, and the optical profile within a defined distance on the surface is measured point by point. The long-wavelength values ​​provided in Table 2 represent the variance of the long-wavelength signal amplitude and have been normalized relative to a unitless value in the range of 0 to 100, where 0 depicts the lowest variance (best) and 100 depicts the highest variance (worst). Similarly, the short-term waviness value represents the variance of the shortwave signal amplitude and has been standardized relative to a unitless value in the range of 0 to 100, where 0 depicts the lowest variance (best) and 100 depicts the highest variance (worst).

[0244] Distinctness of Image (DOI): This is a measure of the clarity and sharpness of a reflected image within a coated surface. In this paper, it is measured using ASTM D5767-18, the Standard Test Method for Instrumental Measurement of Distinctness-of-Image (DOI) Gloss of Coated Surfaces. The scale values ​​obtained using this test method range from 0 to 100, where a value of 100 represents perfect DOI (distinctness of image). As the value decreases from 100, the image becomes increasingly distorted.

[0245] Jacksonville Erosion Grade: The erosion grade of the clear coat was determined by exposing five (5) replicas of clear coat steel plates (30 cm × 30 cm) to the exposure point at Blount Island, Jacksonville, Florida (USA). Exposure lasted from the end of May to the end of August. Defects were rated using a scale ranging from 1 (no visible erosion) to 10 (severe erosion), as detailed in GM Material Specification 9984157 (2009). The erosion grade values ​​were averaged across the five replicas and are presented in Table 2 below. Table 2 Tested characteristics RCC1 RCC2 RCC3 RCC4 CC1 CC2 Image clarity (DOI) 95.5 95.8 96.5 96.5 96.7 96.9 Long-term volatility 4 3.8 4.8 1.7 3.4 1.5 Short-term volatility 2.4 2.1 2.2 1.6 2.0 1.4 Jacksonville erosion level 7.5 6.9 7.0 7.2 6.1 6.4

[0246] Compared to the reference coating compositions RCC1 and RCC2, the addition of polyester resin to CC1 produces an improved appearance, as reflected in the lower shortwave value and higher DOI value given in Table 2. Furthermore, CC1 exhibits improved resistance to Jacksonville erosion.

[0247] Compared to the reference coating compositions RCC3 and RCC4, the use of methacrylate copolymers in CC1 and CC2 produces an improved appearance, as reflected in the lower shortwave value and higher DOI value given in Table 2. Furthermore, CC1 and CC2 exhibit improved resistance to Jacksonville erosion.

[0248] The presence of the combination of low molecular weight diol and polyester resin in the coating composition CC2 promotes the improvement of both long-term and short-term waviness values ​​without compromising the clarity of the image or significantly impairing the corrosion resistance.

[0249] It should be understood that various variations and modifications of the exemplary specific examples described herein will be apparent to those skilled in the art. Such variations and modifications may be made without departing from the spirit and scope of the subject matter of the invention and without diminishing its intended advantages. Therefore, such variations and modifications are intended to be covered by the appended claims. Furthermore, it should be understood that the features of the subsidiary claims may be embodied in the compositions and methods of each independent claim.

[0250] Upon benefiting from the teachings in the foregoing description, those skilled in the art to which this disclosure pertains will conceive of numerous modifications and other specific examples of the disclosure set forth herein. Therefore, it should be understood that this disclosure is not limited to the specific examples disclosed, and that modifications and other specific examples are intended to be included within the scope of the appended claims. [Simplified Explanation of the Diagram]

[0014] Various other objects, advantages and features of this disclosure will become apparent to those skilled in the art from the following discussion in conjunction with the accompanying drawings, in which: [Figure 1] is a side cross-sectional view of an article according to a first specific embodiment of the present disclosure; and [Figure 2] is a side cross-sectional view of an article according to a second specific embodiment of the present disclosure.

Claims

1. A two-part (2K) waterborne coating composition comprising water; a) a binder portion 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 crosslinking agent portion comprising: at least one polyisocyanate compound having a -NCO side group, wherein the molar ratio of active hydrogen atoms to -NCO groups in the composition is 5:1 to 1:5; wherein the (a2) non-aromatic polyester has a number average molecular weight (Mn) of about 500 to about 5000 Daltons, an acid value of about 0 to about 30 mg KOH / g, a calculated hydroxyl value of about 100 to about 600 mg KOH / g, and a calculated hydroxyl functionality of about 2 to about 8; and wherein the (a1) (meth)acrylate copolymer is a reaction product of monomers in a monomer mixture comprising, based on the total weight of monomers: about 20 to about 60 wt.% of i) at least one hydroxyl-functionalized adduct of a monoepoxide ester and an unsaturated carboxylic acid; about 10 to about 30 wt.% of ii) at least one hydroxyl-functionalized unsaturated monomer different from component i); about 2 to about 6 wt.% of iii) at least one unsaturated acid-functionalized monomer; and about 20 to about 60 wt.% of iv) at least one (meth)acrylate monomer represented by the formula MA: H2C=CGaCO2Ra (MA) wherein: Ga is hydrogen, halogen or methyl; and Ra is: C1-C18 alkyl; C2-C18 heteroalkyl; C3-C18 cycloalkyl; C2-C8 heterocycloalkyl; C2-C8 alkenyl; or C2-C8 alkynyl; about 0 to about 15 wt.% of v) at least one vinyl aromatic monomer; and about 0 to about 20 wt.% of vi) at least one polymerizable unsaturated monomer different from i) to v).

2. The coating composition as claimed in claim 1, wherein: The weight ratio of the solids in (a1) to the solids in (a2) is about 100:1 to about 100:35 and / or the coating composition has a volatile organic compound (VOC) content of up to about 420 g / l, as measured according to ISO 11890-2: 2006.

3. The coating composition of claim 1, wherein the (meth)acrylate monomer of formula (MA) produces a homopolymer with a glass transition temperature (Tg) higher than about 30°C during homopolymerization.

4. The coating composition of claim 1, wherein at least one vinyl aromatic monomer of v) has the formula (VA): where: R1 is H or C1-C4 alkyl; each R2 is independently hydrogen or C1-C4 alkyl; Ar is an unsubstituted phenyl or a phenyl substituted with 1 to 5 substituents, wherein each substituent is independently halogen or C1-C4 alkyl; and n is an integer from 0 to 4; wherein the amount of v) present is about 4 to about 14 wt.% based on the total weight of the monomers in the monomer mixture.

5. The coating composition of claim 1, wherein at least one monomer of the monomer mixture has the formula AM1: R4-C(H)═C(R5)—A—(R6O)[a]—R7 (AM1) where: R4 is H, methyl, CO2H, or CH2CO2H; R5 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(R8)-NH-C(O)-O-, -C6H4(R8)-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(CH2 OH)-O-, -CH2-O-CH2-CH2-CH(OH)-O-, -CH2-O-CH2-CH(CH2OH)-NH- or -CH2-O-CH2-CH2-CH(OH)-NH-; Each R6 is independently a C2-C4 alkylene; the value of [a] is about 5 to about 100; R7 is a C1-C30 alkyl, C1-C30 hydroxyalkyl, C1-C30 aminoalkyl, C3-C18 cycloalkyl, C2-C5 heterocycloalkyl, C2-C20 alkenyl, C2-C12 alkynyl, C6-C18 aryl, C7-C24 alkylaryl or C7-C24 aralkyl; and R8 is -CH2- or -(C)(CH3)2-.

6. The coating composition of claim 1, wherein the (a1) hydroxyl-functional (meth)acrylate copolymer is prepared from the monomer mixture by a skew-feed polymerization method using at least two feed monomer streams; and further wherein, A feed stream comprises: I) about 60 to about 100 wt% of the total amount of i) in the monomer mixture; II) about 0 to about 60 wt% of the total amount of ii) in the monomer mixture; III) about 0 to about 30 wt% of the total amount of iii) in the monomer mixture; IV) about 0 to about 80 wt% of the total amount of iv) in the monomer mixture; V) about 0 to about 100 wt% of the total amount of v) in the monomer mixture; and VI) about 0 to about 100 wt% of the total amount of vi) in the monomer mixture, wherein the remaining one or more feed streams comprise the remainder of i) to vi).

7. The coating composition of claim 1, wherein the (a2) non-aromatic polyester has: 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 value of about 250 to about 400 mg KOH / g; and a calculated hydroxyl functionality of about 4 to about 8; and wherein the non-aromatic polyester is obtained by a polycondensation reaction of: at least one hydroxyl functional component (a2h); at least one carboxyl functional component (a2c); and, if desired, at least one hydroxycarboxylic acid component (a2hc), wherein the polycondensation reaction utilizes an excess of hydroxyl groups relative to the stoichiometry of the carboxyl group.

8. The coating composition of claim 1, wherein, based on (a1) by weight, portion a) further comprises, in an amount of up to 20 wt.%, of: (a3) ​​at least one (meth)acrylate polymer having an active hydrogen group, which is different from the (etc.) hydroxyl-functional (meth)acrylate polymer of (a1), wherein (a3) ​​has a water solubility of less than about 6 g / 100 ml water at about 20°C, a calculated hydroxyl value of about 100 to about 600 mg KOH / g, an acid value of about 0 to about 35 mg KOH / g, and a number average molecular weight of about 1000 to about 4000 Daltons.

9. A cured product obtained from the waterborne coating composition of claim 1.

10. A multilayer coated article comprising: a metal substrate, wherein the multilayer coating is disposed on the metal substrate, and wherein the multilayer coating comprises: a primer layer disposed on the substrate and in direct contact with the substrate; at least one base coat layer comprising a compound imparting color and / or visual effect, wherein the at least one base coat layer is disposed on the primer layer and in direct contact with the primer layer; and a clear coat layer comprising a cured product as claimed in claim 9 and disposed on the at least one base coat layer and in direct contact with the at least one base coat layer.

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