RU2781645C1 - Coating composition providing high staining resistance - Google Patents

Abstract

FIELD: building.

SUBSTANCE: invention can be used to manufacture a staining-resistant coating for wood, concrete, or plaster. Coating composition contains an aqueous dispersion of self-crosslinking particles with a core-shell structure, and a hydrophobic additive. The core-shell particles contain an encapsulated polymer core covalently bound with a polymer shell containing urethane bonds, keto and/or aldo functional groups and hydrazide functional groups. The hydrophobic additive is non-reactive, has a polymer core and a polymer shell, and constitutes a wax and/or a silicon-containing compound. Also proposed are a substrate with an at least partially applied coating and a method for increasing the staining resistance of the substrate.

EFFECT: increase in the resistance of the outer coating produced from the proposed composition to staining caused by the entry of dirt from the environment.

20 cl, 2 tbl, 7 ex

Description

The present invention relates to a coating composition containing an aqueous dispersion of self-crosslinking core-shell particles and a hydrophobic additive, to a substrate coated therewith, and to a method for improving the stain resistance of the substrate.

State of the art

Coating compositions for outdoor substrates, such as those covering wood, concrete or plaster, and other coatings are usually stained as a result of exposure to dirt and other materials from the environment. Stain resistance refers to resistance to staining, difficulty in soiling wetting, difficulty in sticking stains, and/or ease of stain removal without damaging the coating.

Disclosure of invention

The present invention relates to a coating composition comprising: an aqueous dispersion of self-crosslinking core-shell particles, wherein the core-shell particles comprise (1) a polymer core at least partially encapsulated by (2) a polymer shell containing urethane bonds, keto - and/or aldo-functional groups and hydrazide functional groups, wherein the polymer core is covalently bonded to at least part of the polymer shell, and a hydrophobic additive containing a wax and/or silicon-containing compound, the hydrophobic additive being non-reactive with the polymer core and the polymer shell.

The present invention also relates to a method for improving the stain resistance of a substrate, comprising: preparing a coating composition by: preparing an aqueous dispersion of self-crosslinking core-shell particles, wherein the core-shell particles comprise (1) a polymer core, at least partially encapsulated (2) with a polymer shell containing urethane linkages, keto and/or ald functional groups and hydrazide functional groups, wherein the polymer core is covalently bonded to at least a portion of the polymer shell; and adding a hydrophobic additive containing wax and/or silicon-containing compound to the aqueous dispersion; and applying the coating composition to the substrate.

Implementation of the invention

For the purposes of the following detailed description, it should be understood that the invention may contemplate various alternatives and sequences of steps, except where expressly stated otherwise. Moreover, with the exception of any working examples or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the description and claims, should be understood as modified in all cases by the term "about". Accordingly, unless otherwise indicated, the numerical parameters set forth in the following description and the appended claims are approximate values that may vary depending on the desired properties to be achieved using the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of significant digits indicated and using normal rounding techniques.

Although the numerical ranges and parameters defining the broad scope of the invention are approximate values, the numerical values set forth in the specific examples are given as accurately as possible. However, any numerical value essentially contains certain errors, necessarily resulting from the standard deviation found in the respective test measurements.

It should also be understood that any numerical range provided herein is intended to include all subranges contained therein. For example, the range "1 to 10" is intended to include all sub-ranges between a specified minimum value of 1 and a specified maximum value of 10 (inclusive), i.e. having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

In this application, the use of the singular includes the plural, and the plural includes the singular unless specifically stated otherwise. In addition, in this application, the use of "or" means "and/or", unless specifically stated otherwise, even though "and/or" may be used explicitly in certain cases. In addition, in this application, the use of the singular means "at least one" unless specifically stated otherwise. For example, "coating", "particle with a core-shell structure", etc. refer to one or more of these elements. In addition, as used herein, the term "polymer" is intended to refer to prepolymers, oligomers, and both homopolymers and copolymers. The term "resin" is used interchangeably with "polymer".

As used herein, the transitional term "comprising" (and other comparable terms such as "comprising" and "including") is "non-limiting" and open to include unspecified entities. Even if something is described using the term "comprising", the terms "consisting essentially of" and "consisting of" are also included in the scope of this invention.

The present invention relates to a coating composition comprising: an aqueous dispersion of self-crosslinking core-shell particles, wherein the core-shell particles comprise (1) a polymer core at least partially encapsulated by (2) a polymer shell. The polymeric shell contains: (i) urethane linkages, (ii) keto and/or aldo functional groups, and (iii) hydrazide functional groups. The polymer core is covalently bonded to at least a portion of the polymer shell. The coating composition contains a hydrophobic additive containing a wax and/or a silicon-containing compound. The hydrophobic additive is non-reactive with a polymer core and a polymer shell.

As used herein, the term "aqueous medium" refers to a liquid medium containing more than 50 weight percent water, based on the total weight of the liquid medium. Such an aqueous liquid medium may contain at least 60 mass percent water, or at least 70 mass percent water, or at least 80 mass percent water, or at least 90 mass percent water, or at least 95 mass percent water, or 100 weight percent water based on the total weight of the liquid medium. Solvents which, if present, comprise up to less than 50 weight percent of the liquid medium include organic solvents. Suitable organic solvents include polar organic solvents, for example protic organic solvents such as glycols, glycol ether alcohols, alcohols, volatile ketones, glycol diesters, esters and diesters. Other suitable organic solvents include aromatic and aliphatic hydrocarbons.

In addition, the term "self-crosslinking" refers to a polymer particle having two or more functional groups that are reactive with each other and that participate in intramolecular and/or intermolecular crosslinking reactions to form a covalent bond in the absence of any external crosslinking agent. Each of the polymer particles of the present invention may contain hydrazide functional groups, as well as keto and/or aldo functional groups, which can react with each other to form hydrazone bonds. As used herein, the terms "crosslinker", "crosslinker" and similar terms refer to a molecule containing two or more functional groups that are reactive with other functional groups and capable of linking two or more monomers or polymer molecules through chemical bonds. It should be understood that self-crosslinking particles with a core-shell structure can also react with crosslinkers separate from them, if they are present.

Each of the water-dispersed (in an aqueous medium) particles with a core-shell structure of the coating composition contains a core that is at least partially encapsulated by a shell. The polymer core may be an acrylic core that is partially bonded to a polyurethane/polyurea shell. The shell may contain a water-dispersible group to be dispersible in an aqueous dispersion. A core-shell particle in which the core is at least partially encapsulated by a shell refers to a particle containing (i) at least a first material or materials that form the center of the particle (i.e., the core) and (ii) at least at least a second material or materials (ie shell) that form a layer on top of at least a portion of the surface of the first material(s) (ie core). It should be understood that the first material(s) that forms the core is different from the second material(s) that forms the shell. In addition, particles with a core-shell structure can have various shapes (or morphologies) and sizes. Particles with a core-shell structure can typically have a spherical, cubic, lamellar, polyhedral or acicular (oblong or fibrous) morphology. The core-shell particles can also have an average particle size of 30 nanometers to 300 nanometers, or 40 nanometers to 200 nanometers, or 50 nanometers to 150 nanometers. Used in this document, the term "average particle size" refers to the volume average particle size. Average particle size can be determined using the Zetasize 3000HS following the instructions in the Zetasize 3000HS manual.

The polymer core typically contains an additive polymer derived from ethylenically unsaturated monomers. The ethylenically unsaturated monomers may include (meth)acrylate monomer, vinyl monomer, or a combination thereof. As such, the polymer core may comprise a (meth)acrylate polymer, a vinyl polymer, or a combination thereof. As used herein, the term "(meth)acrylate" refers to both methacrylate and acrylate. Moreover, the backbone or backbone of the polymer or polymers that form at least part of the polymer shell may contain urea bonds and/or urethane bonds, and optionally may additionally contain other bonds. The polymer shell may comprise a polyurethane with a backbone that contains urethane bonds and urea bonds. As indicated, the polymer shell may also contain additional bonds, including, but not limited to, ester bonds, ether bonds, and combinations thereof.

The polymer core and/or polymer shell contains one or more, for example, two or more reactive functional groups. The term "reactive functional group" refers to an atom, a group of atoms, a functional group, or a group having sufficient reactivity to form at least one covalent bond with another co-reactive group during a chemical reaction. At least some of the reactive functional groups of the polymer shell are keto functional groups (also referred to as ketone functional groups) and/or aldo functional groups (also referred to as aldehyde functional groups), as well as hydrazide functional groups. Optionally, the polymeric core also contains reactive functional groups, such as keto functional groups, aldo functional groups, or combinations thereof. Alternatively, the polymeric core is completely free (ie does not contain) from reactive functional groups, such as keto functional groups and aldo functional groups.

Other suitable additional reactive functional groups that may be present on the polymer shell and/or polymer core include, but are not limited to, carboxylic acid groups, amino groups, epoxy groups, hydroxyl groups, thiol groups, carbamate groups, amide groups, urea groups, isocyanate groups (including blocked isocyanate groups), ethylenically unsaturated groups, and combinations thereof. As used herein, the term "ethylenically unsaturated" refers to a group having at least one carbon-carbon double bond. Suitable ethylenically unsaturated groups include, but are not limited to, (meth)acrylate groups, vinyl groups, and combinations thereof. It should be understood that the polymer shell, the polymer core, or both, may be completely free (ie, not contain) of any additional reactive functional groups.

The polymer core and polymer shell of the core-shell particles can be formed to provide a hydrophilic polymer shell with improved water dispersibility/stability and a hydrophobic polymer core. As used herein, the term "hydrophilic" refers to polymers, monomers, and other materials that have an affinity for water and that will disperse or dissolve more than 1 weight percent of the material in water or other water-based media having a pH greater than 5 at ambient temperature. (20°C-27°C). Hydrophilic materials such as hydrophilic polymers typically have water dispersible groups. "Water dispersible group" refers to a group having or formed from one or more hydrophilic functional groups that have an affinity for water and help disperse a compound, such as a polymer, in water or other aqueous media. In addition, as used herein, the term “hydrophobic” refers to polymers, monomers, and other materials that have no affinity for water or other aqueous media and tend to be repellent, non-soluble, dispersible, and/or non-wettable in water or other aqueous media. water based. Hydrophobic materials, such as hydrophobic polymers, often contain no water-dispersible groups at all.

As stated, the polymer core and polymer shell of the core-shell particles can be formulated to provide a hydrophilic polymer shell with improved water dispersibility/stability and a hydrophobic polymer core. Thus, the polymer shell may contain hydrophilic water-dispersible groups, while the polymer core may contain no hydrophilic water-dispersible groups at all. The hydrophilic water dispersible groups can increase the water dispersibility/stability of the polymer shell in an aqueous environment such that the polymer shell at least partially encapsulates the hydrophobic core.

As previously described, water-dispersible groups contain one or more hydrophilic functional groups. The polymer(s) which(s) form(s) the hydrophilic polymer shell may contain ionic or ionogenic groups such as acidic groups, for example carboxylic acid functional groups or salts thereof. A carboxylic acid functional group can be introduced by using a diol containing a carboxylic acid group to form a polymer shell. Acid groups, such as carboxylic acid functional groups, can be at least partially neutralized (ie, at least 30% of the total neutralization equivalent) with an organic or inorganic base, such as a volatile amine, to form a salt group. Volatile amine refers to an amine compound having an initial boiling point less than or equal to 250° C., measured at a standard atmospheric pressure of 101.3 kPa. Suitable volatile amines include, but are not limited to, ammonia, dimethylamine, trimethylamine, monoethanolamine, and dimethylethanolamine. It should be understood that amines will evaporate during coating formation to open acidic groups such as carboxylic acid functional groups and allow acidic groups such as carboxylic acid functional groups to further react with, for example, a crosslinking agent reactive with acidic groups or carboxylic acid functional groups. Other water dispersible groups include polyoxyalkylene groups, for example when using polyethylene/propylene glycol ether based materials.

The polymeric shell may be formed from (i) polyurethanes containing pendant and/or terminal keto and/or alo functional groups, as well as pendant and/or terminal carboxylic acid functional groups, and (ii) polyurethanes containing pendant and/or terminal hydrazide functional groups, as well as pendant and/or terminal carboxylic acid functional groups. As previously described, carboxylic acid functional groups can be at least partially neutralized (i.e., at least 30% of the total neutralization equivalent) with an organic or inorganic base, such as a volatile amine, to form a salt group, as previously described. In addition, the polymeric core may be a hydrophobic core that is completely free of such carboxylic acid groups and salt groups formed therefrom. "Side group" refers to a group that is offshoot from the side of the polymer backbone and is not part of the backbone of the polymer. In contrast, "terminal group" refers to a group at the end of the polymer backbone that is part of the backbone of the polymer.

The polymer shell may contain a fluorine-containing group and/or a silicon-containing group associated with the polymer shell. The fluorine-containing group and/or the silicon-containing group may be copolymerized with the polymer core as well as bonded to the polymer shell. Fluorine-containing groups and/or silicon-containing groups may contain: a fluorofunctional acrylate (methacrylate) such as: tridecafluorooctyl methacrylate, tridodecafluorooctyl methacrylate, and polydimethylsiliconacrylate (methacrylate) (for example, those available in various molecular weights from Shin-Etsu Chemical (Tokyo, Japan)). The fluorine-containing group and/or the silicon-containing group may be linearly bonded on the polymer shell. Fluorine-containing groups and/or silicon-containing groups may include: ethoxylated polydimethylsiloxane (eg, SILSURF A008-UP from Siltech Corporation (Toronto, Canada)) and Capstone AL62 from Chemours Company (Wilmington, Delaware). The use of fluorine-containing groups and/or silicon-containing groups can improve the stain resistance of the coating formed from the coating composition due to their hydrophobic characteristics.

The polymer shell is also covalently bonded to at least a portion of the polymer core. The polymer shell may be covalently bonded to the polymer core by reacting at least one functional group on the monomers and/or prepolymers that are used to form the polymer shell with at least one functional group on the monomers and/or prepolymers that are used to form the polymer shell. kernels. The functional groups may include any of the functional groups described previously, provided that at least one functional group on the monomers and/or prepolymers that are used to form the polymer shell is reactive with at least one functional group on the monomers and/or prepolymers that are used to form the polymer core. For example, the monomers and/or prepolymers that are used to form both the polymer shell and the polymer core may contain at least one ethylenically unsaturated group that react with each other to form a chemical bond. As used herein, the term "prepolymer" refers to a polymer precursor capable of additional reactions or polymerization via one or more reactive groups to form a higher molecular weight or crosslinked state.

Various components can be used to form the core-shell particles of the present invention. The core-shell particles can be formed from isocyanate-functional polyurethane prepolymers, polyamines, hydrazide-functional compounds, and ethylenically unsaturated monomers. Isocyanate-functional polyurethane prepolymers can be prepared by any method known in the art, for example, by reacting at least one polyisocyanate with one or more compounds having functional groups that are reactive with the isocyanate functionality of the polyisocyanate. The reactive functional groups may be active hydrogen containing functional groups such as hydroxyl groups, thiol groups, amino groups, hydrazide groups, and acidic groups such as carboxylic acid groups. The hydroxyl group may react with the isocyanate group to form a urethane bond. The primary or secondary amino group may react with the isocyanate group to form a urea bond. Suitable compounds that can be used to form the polyurethane include, but are not limited to, polyols, polyisocyanates, compounds containing one or more carboxylic acid groups such as diols containing one or more carboxylic acid groups, polyamines, ethylenically unsaturated hydroxyl-functional components , such as hydroxyalkyl esters of (meth)acrylic acid and/or other compounds having reactive functional groups such as hydroxyl groups, thiol groups, amino groups and carboxylic acid groups. The polyurethane prepolymer can also be prepared using keto- and/or aldo-functional monoalcohols.

Suitable polyisocyanates include, but are not limited to, isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (H12MDI), cyclohexyl diisocyanate (CHDI), m-tetramethylxylylene diisocyanate (m-TMXDI), p-tetramethylxylylene diisocyanate (p-TMXDI), ethylene diisocyanate . (MXDI) and p-xylylene diisocyanate, 4-chloro-1,3-phenylenediisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 4,4'-dibenzyl diisocyanate and 1,2,4-benzene triisocyanate, xylylene diisocyanate (XDI) and mixtures or combinations thereof.

Polyols that can be used to form a polyurethane-based polymer such as a polyurethane prepolymer include, but are not limited to, lower molecular weight glycols (number average molecular weight (Mn) less than 5,000), polyether polyols, polyester polyols, copolymers thereof. and their combinations. As reported in this document, Mn is measured by gel permeation chromatography using a polystyrene standard according to ASTM D6579-11 (performed using a Waters 2695 separation module with a Waters 2414 differential refractometer (RI detector); tetrahydrofuran (THF) was used as eluent at flow rate of 1 ml/min, and two columns of PLgel Mixed-C (300 x 7.5 mm) were used for separation at room temperature, the weight average and number average molecular weight of polymer samples can be measured by gel permeation chromatography against a linear polystyrene standard of 800 Yes up to 900,000 Yes). Low molecular weight glycols include, but are not limited to, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, and combinations thereof, as well as other compounds that contain two or more hydroxyl groups and combinations of any of the above. Suitable polyether polyols include, but are not limited to, polytetrahydrofuran, polyethylene glycol, polypropylene glycol, polybutylene glycol, and combinations thereof. Polyether polyols include those derived from a polyol containing an ether moiety and a carboxylic acid or anhydride.

Other suitable polyols include, but are not limited to, cyclohexanedimethanol, 2-ethyl-1,6-hexanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, trimethylolpropane, 1,2,6-hexanetriol, glycerin, and combinations thereof. . In addition, suitable amino alcohols that can be used include, but are not limited to, ethanolamine, propanolamine, butanolamine, and combinations thereof.

Suitable carboxylic acids that can react with polyols to form a polyester polyol include, but are not limited to, dibasic acids such as glutaric acid, succinic acid, malonic acid, oxalic acid, phthalic acid, isophthalic acid, hexahydrophthalic acid, adipic acid , maleic acid and mixtures thereof. Suitable diols containing acids include, but are not limited to, 2,2-bis(hydroxymethyl)propionic acid, which is also referred to as dimethylolpropionic acid (DMPA), 2,2-bis(hydroxymethyl)butanoic acid, which is also referred to as dimethylolbutanoic acid. acid (DMBA), diphenolic acid, and combinations thereof.

Suitable hydrazide functional materials that can be used in the preparation of the polyurethane prepolymer and to provide hydrazide functionality may include dihydrazide functional compounds such as, but not limited to, maleic dihydrazide, fumaric dihydrazide, itacone dihydrazide, phthalic dihydrazide, isophthalic dihydrazide, terephthalic dihydrazide, trimellitic trihydrazide, oxalate dihydrazide, adipic acid dihydrazide, sebacic dihydrazide, and combinations thereof.

Keto-functional monoalcohols that can be used in the preparation of the polyurethane prepolymer and to provide keto and/or aldo functionality include, but are not limited to, hydroxyacetone, 4-hydroxy-2-butanone, 5-hydroxy-4- octanone, 4-hydroxy-4-methylpentan-2-one, which is also referred to as diacetone alcohol, 3-hydroxyacetophenone, and combinations thereof. Suitable aldo-functional monoalcohols include, but are not limited to, DL-lactaldehyde solution, 3-hydroxybutanal, 4-hydroxypentanal, 5-hydroxyhexanal, 5-hydroxy-5-methylhexanal, 4-hydroxy-4-methylpentanal, 3-hydroxy-3 -methylbutanal and combinations thereof.

Compounds that can be used to incorporate ethylenically unsaturated moieties into the polyurethane prepolymer include, but are not limited to, hydroxyalkyl esters of (meth)acrylic acid such as hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate and combinations thereof.

The components that form the polyurethane prepolymer may be reacted in a stepwise manner or may be reacted simultaneously. The polyurethane prepolymer can be formed by reacting a diisocyanate, a polyol, a diol containing a carboxyl group, an ethylenically unsaturated monomer containing a hydroxyl group, and a dihydrazide functional compound.

As previously mentioned, core-shell particles can also be made using polyamines and ethylenically unsaturated monomers not included in the polyurethane at the time of manufacture. For example, isocyanate-functional polyurethane prepolymers can be prepared as described above and then reacted with polyamines as a chain extender. As used herein, the term "chain extender" refers to a lower molecular weight compound (a compound having a Mn of less than 1000) containing two or more functional groups that are reactive with isocyanate.

Suitable polyamines that can be used to form a polyurethane-based polymer include aliphatic and aromatic compounds that contain two or more amino groups selected from primary and secondary amino groups, including, but not limited to, diamines such as ethylenediamine, hexamethylenediamine, 1, 2-propanediamine, 2-methyl-1,5-penta-methylenediamine, 2,2,4-trimethyl-1,6-hexanediamine, isophoronediamine, diaminocyclohexane, xylylenediamine, 1,12-diamino-4,9-dioxadodecane and combinations thereof . Suitable polyamines are also sold by Huntsman Corporation (Woodland, Texas) under the JEFFAMINE trade name, such as JEFFAMINE D-230 and JEFFAMINE D-400.

Other suitable polyamine-functional compounds include, but are not limited to, Michael addition reaction products of a polyamine-functional compound, such as a diamine, with keto- and/or aldo-containing ethylenically unsaturated monomers. A polyamine-functional compound typically contains at least two primary amino groups (i.e., a functional group represented by the structural formula -NH ₂ ), and keto- and/or aldo-containing unsaturated monomers include, but are not limited to, (meth) acrolein, diacetone (meth)acrylamide, diacetone (meth)acrylate, acetoacetoxyethyl (meth)acrylate, vinylacetoacetate, crotonaldehyde, 4-vinylbenzaldehyde, and combinations thereof. The resulting Michael addition reaction products may include a compound with at least two secondary amino groups (i.e., a functional group represented by the structural formula -NRH, in which R is a hydrocarbonyl) and at least two keto and/or aldo functional groups. It should be understood that the secondary amino groups will react with the isocyanate functional groups of the polyurethane prepolymers to form urea bonds and extend the chain of the polyurethanes. In addition, the keto and/or aldo functional groups will move away from the main chain of the chain extended polyurethane, for example from the urea nitrogen atom, to form the keto and/or aldo functionalized polyurethane.

As indicated and in accordance with the present invention, the aqueous dispersion contains particles with a core-shell structure, which have a polymer shell containing keto and/or ald functional groups, as well as hydrazide functional groups. The polymer shell of such particles with a core-shell structure can be obtained using polymers with hydrazide functional groups and polymers with keto and/or aldo functional groups, or polymers that contain both a hydrazide functional group and a keto and/or aldo functional group. functional group. The polymers may also contain additional functional groups as previously described, including but not limited to ethylenically unsaturated groups. The polymer shell of such particles with a core-shell structure can be obtained using: (i) a first polyurethane containing urethane linkages, water-dispersible groups such as carboxylic acid groups, ethylenically unsaturated groups and hydrazide groups; and (ii) a second polyurethane containing urethane linkages, water dispersible groups such as carboxylic acid groups, ethylenically unsaturated groups, keto and/or aldo functional groups, and optionally urea bonds.

Moreover, the first and second polyurethanes can be obtained using the previously described components. The first polyurethane can be obtained by reacting an isocyanate and ethylenically unsaturated polyurethane and a dihydrazide functional compound such as adipic acid dihydrazide. The second polyurethane can be prepared by reaction and chain extension of isocyanate- and ethylenically-unsaturated polyurethanes and the Michael addition reaction product of diamine and keto- and/or ald-containing ethylenically unsaturated monomers. The isocyanate- and ethylenically-unsaturated polyurethanes used to form the first and second polyurethanes can be formed from polyols, polyisocyanates, carboxylic acid-functional diols, and hydroxyl-functional ethylenically unsaturated components.

After the formation of the polyurethane(s) (eg, the first and second polyurethanes described previously), the polyurethane(s) and additional ethylenically unsaturated monomers can be subjected to a polymerization process to form core-shell particles. Additional ethylenically unsaturated monomers may be added after the formation of the polyurethane(s). Alternatively, additional ethylenically unsaturated monomers may be used as a diluent during the production of the polyurethane(s) and not added after the formation of the polyurethane(s). It should be understood that the ethylenically unsaturated monomers can be used as a diluent during the production of the polyurethane(s) as well as added after the formation of the polyurethane(s).

Additional ethylenically unsaturated monomers may include multiethylenically unsaturated monomers, monoethylenically unsaturated monomers, or combinations thereof. "Monoethylenically unsaturated monomer" refers to a monomer containing only one ethylenically unsaturated group, and "multiethylenically unsaturated monomer" refers to a monomer containing two or more ethylenically unsaturated groups.

Suitable ethylenically unsaturated monomers include, but are not limited to, (meth)acrylic acid alkyl esters, (meth)acrylic acid hydroxyalkyl esters, acid group-containing ethylenically unsaturated monomers, vinylaromatic monomers, aldo- or keto-containing ethylenically unsaturated monomers, and combinations thereof.

Suitable (meth)acrylic acid alkyl esters include, but are not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate , octyl (meth)acrylate, glycidyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, vinyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, acetoacetoxypropyl (meth)acrylate, and combinations thereof. Other alkyl esters include di(meth)acrylate alkyl diesters formed by the condensation of two equivalents of (meth)acrylic acid and a diol, such as ethylene glycol di(meth)acrylate. Di(meth)acrylate alkyl diesters derived from C _2-24 diols such as butanediol and hexanediol can also be used.

Suitable hydroxyalkyl esters of (meth)acrylic acid and keto- and aldo-containing ethylenically unsaturated monomers include, but are not limited to, any of those previously described. Suitable ethylenically unsaturated monomers containing acidic groups include, but are not limited to, (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, aspartic acid, malic acid, mercaptosuccinic acid, and combinations thereof.

Suitable vinylaromatic monomers include, but are not limited to, styrene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, vinylnaphthalene, vinyltoluene, divinyl aromatic monomers such as divinylbenzene, and combinations thereof.

As noted earlier, ethylenically unsaturated monomers can be polymerized in the presence of polyurethane(s), which may also contain ethylenically unsaturated groups, to form core-shell particles. Polymerization can be carried out using methods recognized in the art, as well as conventional additives such as emulsifiers, protective colloids, free radical polymerization initiators and chain transfer agents known in the art.

The core-shell particles of the present invention can be made with: (i) ethylenically unsaturated monomers; (ii) a first polyurethane containing urethane linkages, carboxylic acid groups, ethylenically unsaturated groups and hydrazide groups; and (iii) a second polyurethane containing urethane bonds, urea bonds, carboxylic acid groups, ethylenically unsaturated groups, and keto and/or aldo groups. In addition, the resulting core-shell particles contain a polymer core derived from ethylenically unsaturated monomers and may contain an addition polymer formed by free radical polymerization from a monomeric component that may contain any of the ethylenically unsaturated monomers mentioned previously, which is covalently bonded to at least part of a polyurethane shell having lateral carboxylic acid functional groups, lateral or terminal keto and/or aldo functional groups, hydrazide functional groups, urethane bonds and urea bonds. For improved water dispersibility/stability, carboxylic acid functionality on the polymer shell can be at least partially neutralized (i.e., at least 30% of the total neutralization equivalent) with an organic or inorganic base such as a volatile amine to form a salt group as described previously. The polymeric core may also contain pendant and/or terminal functional groups, such as keto and/or aldo functional groups, using ethylenically unsaturated monomers that contain additional functional groups, such as ethylenically unsaturated monomers containing acidic groups and/or ethylenically unsaturated monomers. containing aldo or keto groups as above. Alternatively, the polymeric core may be completely free of additional functional groups, for example, completely free of keto and/or aldo functional groups. In addition, the polymer core is covalently bonded to at least a portion of the polymer shell after polymerization of the monomers and polyurethane(s).

The polymer core of the core-shell particle may have a Tg of 10°C to 30°C, such as 10°C to 20°C, 20°C to 30°C, 15°C to 30°C, or 15°C to 25°C as measured by differential scanning calorimetry in accordance with ASTM D3418-15. The Tg referred to in this paragraph refers to the Tg of the polymeric core of the core-shell particle prior to encapsulation by the polymeric shell.

It should be understood that the core-shell particles described herein are dispersed in an aqueous medium to form a latex. As used herein, the term "latex" in relation to aqueous dispersion particles with a core-shell structure refers to an aqueous colloidal dispersion of polymer particles.

In addition to the above-described aqueous dispersion of self-crosslinking particles with a core-shell structure, the coating composition contains a hydrophobic additive containing wax and/or a silicon-containing compound. This hydrophobic additive may be non-reactive with the polymer core and polymer shell of the self-crosslinking core-shell particles.

The coating composition comprising self-crosslinking core-shell particles and a hydrophobic additive may contain self-crosslinking core-shell particles in an amount of at least 60 weight percent, at least 70 weight percent, or at least 80 weight percent of the composition for coatings based on the total weight of solids of the coating composition. The self-crosslinking core-shell particles can comprise up to 90 weight percent, up to 80 weight percent, or up to 70 weight percent of the coating composition, based on the total solids weight of the coating composition. The self-crosslinking core-shell particles may also be included in the coating composition in a range such as 60 wt% to 90 wt%, or 65 wt% to 90 wt%, or 70 wt% to 90 wt%, or 75 wt% to 90 wt%, or 75 wt% to 80 wt%, or 70 wt% to 80 wt%, or 60 wt% to 80 wt% of the coating composition based on the total weight of composition solids for coverage.

The coating composition comprising the self-crosslinking core-shell particles and the hydrophobic additive may contain the hydrophobic additive in an amount of at least 10 weight percent, at least 20 weight percent, or at least 30 weight percent of the coating composition, based on total the weight of solids of the coating composition. The hydrophobic additive may comprise up to 40 weight percent, up to 30 weight percent, or up to 20 weight percent of the coating composition, based on the total solids weight of the coating composition. The hydrophobic additive may also be included in the coating composition in a range such as 10 wt% to 40 wt%, or 15 wt% to 40 wt%, or 20 wt% to 40 wt%, or 25 wt% to 40 wt %, or 25 wt % to 30 wt %, or 20 wt % to 30 wt %, or 10 wt % to 30 wt % of the coating composition, based on the total solids weight of the coating composition.

The hydrophobic additive may contain a wax or lubricant. Wax can be defined as a lipid composed of a chain of alkanes or esters of alcohols and fatty acids. The wax may include an anionic polyethylene and/or paraffin emulsion. The wax may include unfiltered paraffin wax. Non-limiting commercial examples of a hydrophobic wax or lubricant include, but are not limited to: SLIP-AYD SL 18, SLIP-AYD SL 1606, SLIP-AYD SL-300 (Elementis Specialties (London, England)); MICHEMLUBE 368, MICHEMLUBE 743, MICHEMLUBE 511, MICHEM Emulsion 39235 (Michelman, Inc. (Cincinnati, Ohio)); POLIGEN ES 91009, POLIGEN ES 91012 (BASF (Ludwigshafen, Germany)); SUNPAR 110 (HollyFrontier Corporation (Dallas, Texas)); and AQUACER 539 (BYK Chemie GmbH (Wesel, Germany)).

The hydrophobic additive may contain a silicon-containing compound. The silicon-containing compound may contain a polysiloxane modified with a functional silicone resin. Non-limiting commercial examples of a silicon-containing compound include, but are not limited to: SILRES BS 1306, SILRES BS 50, SILRES BS 1340, SILRES WH (Wacker Chemie AG (Munich, Germany)); and BYK-333, BYK-321 (BYK Chemie GmbH (Wesel, Germany)).

The coating composition may also optionally contain additional components.

The coating composition may contain an acrylic polymer derived from ethylenically unsaturated monomers, which may include polyethylene unsaturated monomers.

Suitable ethylenically unsaturated monomers with only one site of unsaturation for the preparation of an acrylic polymer, ie. monoethylenically unsaturated monomers include, but are not limited to, styrene, alpha-methylstyrene, vinyltoluene, 4-methylstyrene, tert-butylstyrene, 2-chlorostyrene, vinylpyridine, vinylpyrrolidone, methyl crotonoate, sodium crotonoate, ethyl acrylate, propylacrylate, isopropylacrylate, butyl acrylate, 2-ethylhexyl acrylate , децилакрилат, гидроксиэтилакрилат, метилметакрилат, этилметакрилат, пропилметакрилат, изопропилметакрилат, бутилметакрилат, втор-бутилметакрилат, изобутилметакрилат, н-амилметакрилат, изоамилметакрилат, н-гексилметакрилат, трет-бутилметакрилат, 2-этилгексилметакрилат, н-октилметакрилат, металлилметакрилат, фенилметакрилат, бензилметакрилат, аллилметакрилат , cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, 2-sulfoethyl methacrylate, trifluoroethyl methacrylate, glycidyl methacrylate, 2-n-butoxyethyl methacrylate, 2-chloroethyl methacrylate, 2-ethyl methacrylate , cyclopene tyl methacrylate, 2-ethoxyethyl methacrylate, furfuryl methacrylate, hexafluoroisopropyl methacrylate, 3-methoxybutyl methyl methacrylate, 2-methoxybutyl methyl methacrylate, 2-nitro-2-methylpropyl methyl methacrylate, 2-phenoxyethyl methyl methacrylate, 2-phenylethyl methacrylate, propargyl methacrylate, tetrahydrofurfuryl methacrylate, tetrahydropyranyl methacrylate, N -methylmethacrylamide, N-ethylmethacrylamide, N,N-diethylmethacrylamide, N,N-dimethylmethacrylamide, N-phenylmethacrylamide, acrylamide, N,N-diethylacrylamide, N-ethylacrylamide, methyl-2-cyanoacrylate, methyl-α-chloacrylonrylate, methacrolein, acrolein , methacrylonitrile and acrylonitrile.

Specific non-limiting examples of polyethylene unsaturated monomers include, but are not limited to, diacrylates such as 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate, 1,4-butanediol dimethacrylate, poly(butanediol), tetraethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, triethylene glycol diacrylate, triisopropylene glycol diacrylate, polyethylene glycol diacrylate and/or bisphenol A dimethacrylate; triacrylates such as trimethylol propane triacrylate, trimethylol propane trimethacrylate, pentaerythritol monohydroxy triacrylate and/or trimethylol propane triethoxy triacrylate; tetraacrylates such as pentaerythritol tetraacrylate and/or ditrimethylol propane tetraacrylate; and/or pentaacrylates such as dipentaerythritol (monohydroxy) pentaacrylate.

The acrylic polymer can be produced by aqueous emulsion polymerization methods or organic solution polymerization methods with groups capable of forming salts, such as acidic groups or amino groups. After neutralization of these groups with base or acid, the polymers can be dispersed in an aqueous medium to form a latex. The acrylic polymer may have a Mw of at least 100,000.

Non-limiting examples of suitable acrylic polymers include, but are not limited to, RHOPLEX SG-30, RHOPLEX PR-33, RHOPLEX 585, available from Dow Chemical Company (Midland, MI).

The acrylic polymer may be non-reactive with a polymer core and a polymer shell of self-crosslinking particles with a core-shell structure. The acrylic polymer can be added to the aqueous dispersion after the formation of self-crosslinking core-shell particles.

The coating composition may also contain non-self-crosslinking core-shell particles. As used herein, the term "non-self-crosslinking" refers to a polymer particle having one or more functional groups that are not reactive with each other and which thus require one or more external crosslinkers to proceed with the crosslinking reaction. The non-self-crosslinking core-shell particles may contain a polymeric core containing: (i) residues of ethylenically unsaturated monomers such as (meth)acrylate monomers, vinyl monomers, or a combination thereof, and therefore contain an addition polymer such as a (meth)acrylate polymer , vinyl polymer, or a combination thereof; and (ii) keto and/or aldo functional groups. Moreover, the backbone or backbone of the polymer(s) that forms at least a portion of the polymer shell may contain urethane linkages and optionally other linkages such as ester linkages, ether linkages, and combinations thereof. Thus, the polymeric core may contain keto and/or aldo functionalities and the polymeric shell may contain polyurethane(s) which are completely free of keto and/or aldo functionalities and optionally completely free of urea bonds. In addition, both the polymer core and the polymer shell may be completely free of hydrazide functional groups. It should be understood that such non-self-crosslinking core-shell particles can be made from materials similar to those described above for self-crosslinking core-shell particles.

The non-self-crosslinking core-shell particles may also comprise a polymeric core containing an addition polymer such as (meth)acrylate polymer, vinyl polymer, or a combination thereof, which is derived from ethylenically unsaturated monomers, such as (meth)acrylate monomers, vinyl monomers, or a combination thereof. , and a polymeric shell containing urethane bonds, water-dispersible groups such as carboxylic acid groups, ethylenically unsaturated groups, keto and/or aldo groups, and optionally urea bonds. Moreover, the backbone or backbone of the polymer(s) that forms at least part of the polymer shell may optionally contain other linkages such as ester linkages, ether linkages, and combinations thereof. In addition, the obtained particles with a core-shell structure contain a polymer core derived from ethylenically unsaturated monomers, which is covalently associated with at least a part of the polyurethane shell having side carboxylic acid functional groups, side or terminal keto and/or aldo functional groups, urethane bonds, and optionally urea bonds. For improved water dispersibility/stability, the carboxylic acid functionality on the polymer shell can be at least partially neutralized (i.e., at least 30% of the total neutralization equivalent) with an organic or inorganic base, such as a volatile amine, to form a salt group, as described earlier. The polymeric core may also contain pendant and/or terminal functional groups, such as keto and/or aldo functional groups, using ethylenically unsaturated monomers that contain additional functional groups, as discussed above in relation to self-crosslinking particles with a core-shell structure. Alternatively, the polymer core may be completely free of additional functional groups, such as keto and/or aldino functional groups. In addition, both the polymer core and the polymer shell may be completely free of hydrazide functional groups. It should be understood that such core-shell particles can be made from materials similar to those described above for self-crosslinking core-shell particles.

The non-self-crosslinking core-shell particles may comprise at least 0.1 weight percent, at least 1 weight percent, at least 2 weight percent, at least 5 weight percent, or at least 10 weight percent of the resin blend, calculated on the total weight of resin solids. The non-self-crosslinking core-shell particles can comprise up to 40 weight percent, up to 30 weight percent, or up to 20 weight percent of the resin mixture, based on the total weight of resin solids. The non-self-crosslinking core-shell particles may also be contained in a range such as 0.1 mass percent to 40 mass percent, or 1 mass percent to 30 mass percent, or 2 mass percent to 20 mass percent, based on the total weight of resin solids.

The coating composition may also contain one or more cross-linking agents. For example, the coating composition of the present invention may contain at least one crosslinking agent that is reactive with the functional groups of the non-self-crosslinking core-shell particles described above and/or optional additional film-forming resins described later herein. Suitable crosslinking agents include, but are not limited to, polyhydrazides, carbodiimides, polyols, phenolic resins, epoxy resins, beta-hydroxy (alkyl) amide resins, hydroxy (alkyl) urea resins, oxazolines, alkylated carbamate resins, (meth)acrylates, isocyanates , blocked isocyanates, polyacids, anhydrides, acid-functional organometallic materials, polyamines, polyamides, aminoplasts, aziridines, and combinations thereof.

The crosslinker(s) agent(s) may react with the core-shell particles to assist in curing the coating composition. The terms "curable", "curable", etc. mean that at least a portion of the resinous materials in the composition is crosslinked or crosslinkable. Cure or degree of cure can be determined by dynamic mechanical thermal analysis (DMTA) using a Polymer Laboratories MK III DMTA analyzer run under nitrogen. The degree of cure may be at least 10%, such as at least 30%, such as at least 50%, such as at least 70%, or at least 90% of complete crosslinking, as determined by the above analysis.

In addition, curing can take place under ambient conditions, with heat, or by other means such as actinic radiation. As used herein, "ambient conditions" refers to environmental conditions such as temperature, humidity, and pressure in a room or outside environment. The coating composition can be cured at room temperature (eg 20°C-27°C) within 24 hours. In addition, the term "actinic radiation" refers to electromagnetic radiation that can initiate chemical reactions. Actinic radiation includes, but is not limited to, visible light, ultraviolet (UV) light, infrared and near infrared radiation, x-rays and gamma rays.

The coating composition may contain at least one cross-linking agent that is reactive with: (i) keto and/or aldo functional groups or hydrazide functional groups on the polymer shell of the self-crosslinking core-shell particles; and/or (ii) keto and aldo functional groups in the polymeric core and/or shell of the non-self-crosslinking core-shell particles, if present. The crosslinker may also react with functional groups, such as keto and aldo functional groups, which may be present in the polymer core of the self-crosslinking core-shell particles. For example, the coating composition may contain a polyhydrazide that is reactive with the keto and/or aldo functional groups in the polymer shell of the non-self-crosslinking core-shell particles and the keto and/or aldo functional groups in the polymer shell of the self-crosslinking core-shell particles. -shell. The polyhydrazides may include non-polymeric polyhydrazides, polymeric polyhydrazides, or combinations thereof. Suitable non-polymeric polyhydrazides may include the previously described dihydrazide functional compounds.

Polymeric polyhydrazides may include various types of polymers containing two or more hydrazide functional groups. The polymeric polyhydrazide may contain a polyurethane having two or more hydrazide groups. The polyhydrazide-functional polyurethane can be obtained by first forming a water-dispersible isocyanate-functional polyurethane prepolymer. Such water-dispersible isocyanate-functional polyurethane prepolymers can be prepared by reacting polyols, isocyanates, and optionally carboxylic acid-containing compounds such as carboxylic acid-containing diols and/or polyamines. These compounds may include any of the compounds previously described with respect to the polyurethane core-shell particle prepolymer.

It should be understood that the isocyanate-functional polyurethane prepolymer used to make the polyhydrazide-functional polyurethane may include additional functional groups. The isocyanate-functional polyurethane prepolymer may also contain any of the reactive functional groups previously described, such as carboxylic acid groups, which can be at least partially neutralized with an organic or inorganic base to form a salt group and improve the water dispersibility/stability of the polyurethane. The polyurethane prepolymer may also be completely free of any additional functional groups. In addition, the isocyanate-functional polyurethane prepolymer may contain additional bonds other than urethanes, including, but not limited to, ether bonds, ester bonds, urea bonds, and any combination thereof.

After the formation of the water-dispersible isocyanate-functional polyurethane prepolymer, the polyurethane prepolymer reacts with one or more hydrazine and/or polyhydrazide compounds to form the water-dispersible polyhydrazide-functional polyurethane. Hydrazine and polyhydrazide compounds can also extend the chain of the isocyanate-functional polyurethane prepolymer. Suitable polyhydrazide compounds that can react with the isocyanate-functional polyurethane prepolymer include any of the previously described non-polymeric hydrazide-functional compounds.

The polymeric polyhydrazides may also comprise core-shell particles comprising a polymeric core at least partially encapsulated by a polymeric shell having two or more hydrazide functional groups. Polyhydrazide-functional core-shell particles can be prepared by reacting polyurethane prepolymers containing isocyanate and ethylenically unsaturated functional groups with hydrazine and/or polyhydrazide compounds and ethylenically unsaturated monomers and/or polymers. Polyhydrazide-functional core-shell particles can be prepared by reacting isocyanate and ethylenically unsaturated polyurethane prepolymers with hydrazine and/or polyhydrazide compounds to form hydrazide and ethylenically unsaturated polyurethanes. In addition, polyurethanes containing hydrazide and ethylenically unsaturated groups polymerize in the presence of ethylenically unsaturated monomers and/or polymers to form core-shell particles. The resulting core-shell particles will contain a polymeric core derived from ethylenically unsaturated monomers and/or polymers that are covalently bonded to at least a portion of the polyurethane shell containing hydrazide functional groups and urethane bonds. The polymer shell may also contain additional functional groups (eg, carboxylic acid functional groups) and/or bonds (eg, ester bonds and/or ether bonds), as previously described in relation to polyurethane shells. The hydrazide-functional core-shell particles may also be completely free of additional functional groups and bonds, such as any of those previously described herein. It should be understood that the hydrazide-functional core-shell particles that can be used as a cross-linking agent are completely free of keto and aldo functional groups.

The coating composition may also contain at least two different types of crosslinkers that are reactive with functional groups that may be present in the core-shell particles, such as keto and/or aldo functional groups, hydrazide groups and/or carboxylic acid functional groups. The coating composition may contain a keto- and/or aldo-reactive polyhydrazide, such as any of those previously described, and a carboxy-acid-reactive carbodiimide. Some suitable carbodiimides are described in US Patent Application Publication No. 2011/0070374 in paragraphs [0006]-[0105], which is incorporated herein by reference.

In addition, the coating composition may contain additional materials, including, but not limited to, additional resins, such as additional film-forming resins. As used herein, the term "film-forming resin" refers to a resin that, when used in a coating composition, can form a self-supporting continuous film on at least a horizontal surface by dehydration and/or curing. The term "dehydration" refers to the removal of water and/or other solvents. It should be understood that dehydration can also cause at least partial curing of resinous material such as core-shell particles and additional resins described herein. The coating composition containing the additional resin may be dehydrated and/or cured at ambient conditions for 24 hours with heat or other means such as actinic radiation, as previously described.

Additional resin may include any of a variety of thermoplastic and/or thermoset film-forming resins known in the art. The term "thermoset" refers to resins that irreversibly "seize" upon curing or crosslinking, with the polymer chains of the resins bonded to each other by covalent bonds. Once cured or cross-linked, the thermoset resin does not melt when heated and does not dissolve in solvents. As already noted, the film-forming resin may also include a thermoplastic film-forming resin. The term "thermoplastic" refers to resins that are not bound by covalent bonds and thus can undergo fluid flow when heated and can be dissolved in certain solvents.

Suitable additional resins may include polyurethanes other than those previously described, polyesters such as polyester polyols, polyamides, polyethers, polysiloxanes, fluoropolymers, polysulfides, polythioethers, polyureas, (meth)acrylic resins, epoxy resins, vinyl resins, and combinations thereof. . Additional resins may also include non-dispersible resins.

The additional resin may contain any of a variety of reactive functional groups, including, but not limited to, carboxylic acid groups, amino groups, epoxy groups, hydroxyl groups, thiol groups, carbamate groups, amide groups, urea groups, isocyanate groups (including blocked isocyanate groups), (meth)acrylate groups and combinations thereof. Thermoset coating compositions typically contain a crosslinker, which may be selected from any of the crosslinkers known in the art to react with the functionality of the resins used in the coating compositions. Cross-linking agents may include any of those previously described. Alternatively, a thermoset film-forming resin containing functional groups that are reactive with themselves can be used; thus, such thermoset resins are self-crosslinking.

The coating composition may further comprise a mildew preventative. As used herein, a mold preventative is defined as a biocide that inhibits the growth of fungus, mold, algae, bacteria, or some combination thereof, on the surface of the cured coating to which it has been added (the coating composition that forms the coating).

The coating composition may also contain other additional materials such as a colorant. Used in this document, the term "coloring agent" refers to any substance that imparts color and/or other opacity and/or other visual effect to the composition. The colorant may be added to the coating in any suitable form such as discrete particles, dispersions, solutions and/or flakes. The coatings of the present invention may use a single colorant or a mixture of two or more colorants.

Coloring agents may include pigments (organic or inorganic), dyes and shades such as those used in the paint industry and/or listed by the International Pigment Manufacturers Association (DCMA), as well as special effect compositions. The coloring agent may include a fine, dense powder that is insoluble but wettable under conditions of use. The coloring agent may be organic or inorganic and may be agglomerated or non-agglomerated. Coloring agents may be incorporated into the coating using a comminution carrier such as an acrylic comminution carrier, the use of which will be known to those skilled in the art.

Suitable pigments and/or pigment compositions include, but are not limited to, crude carbazoledioxazine pigment, azo, monoazo, diazo, naphthol AS, salt type (flakes), benzimidazolone, isoindolinone, isoindoline and polycyclic phthalocyanine, quinacridone, perylene, perinone, diketopyrrolopyrrole, thioindigo, anthraquinone, indanthrone, anthrapyrimidine, flavantron, pyranthrone, antanthrone, dioxazine, triarylcarbonium, quinophthalone pigments, diketopyrrolopyrrole red ("DPPBO red"), titanium dioxide, carbon black, and mixtures thereof. The terms "pigment" and "colored filler" can be used interchangeably.

Suitable dyes include, but are not limited to, solvent and/or water based dyes such as phthalo green or blue, iron oxide, and bismuth vanadate.

Suitable shades include, but are not limited to, pigments dispersed in aqueous or water-miscible vehicles such as AQUA-CHEM 896 available commercially from Evonik Industries (Essen, Germany), CHARISMA COLORANTS and MAXITONER INDUSTRIAL COLORANTS available. available from Accurate Dispersions Division of Eastman Chemical, Inc. (Kingsport, Tennessee).

The colorant that can be used with the coating composition of the present invention may also include a special effect composition or pigment. As used herein, the term "special effect composition or pigment" refers to a composition or pigment that interacts with visible light to provide an appearance effect other than, or in addition to, a solid permanent color. Suitable special effect compositions and pigments may include those that provide one or more appearance effects such as reflectivity, pearl effect, metallic sheen, texture, phosphorescence, fluorescence, photochromism, light sensitivity, thermochromism, goniochromism, and/or color change. Special effect compositions may include coated transparent mica and/or synthetic mica, coated silica, coated alumina, aluminum flakes, transparent liquid crystal pigment, liquid crystal coating, and combinations thereof.

The coating composition may include a rheology modifier to adjust the viscosity of the coating composition to a desired level. The rheology modifier may be a non-associative rheology modifier such as an inorganic additive (eg, clays) and hydroxyethyl cellulose (HEC). The rheology modifier can be an associative rheology modifier such as hydrophobically modified ethylene oxide (HEUR) urethane or hydrophobically modified alkali soluble emulsion (HASE). The coating composition may have a Stormer viscosity from 40 kE to 120 kE (when measured according to ASTM D562) and/or an ICI viscosity from 0.1 Poise to 5 Poise (when measured according to ASTM D4287).

Additional materials that may optionally be used with the coating composition of the present invention include plasticizers, abrasion resistant particles, antioxidants, hindered amine light stabilizers, UV absorbers and stabilizers, surfactants, flow and surface regulators, thixotropic agents, catalysts, reaction inhibitors and other conventional auxiliaries.

The coating composition of the present invention, when applied to a substrate and dried to form a coating, can improve the stain resistance of the coating compared to the same coating composition that does not contain self-crosslinking core-shell particles. The stain resistance of the cured coating can be determined as described in the test method indicated in the following examples, and the cured coating stain resistance can be such that the cured coating has an ΔE of not more than 10, for example, not more than 7.5, not more than 7, no more than 6 or no more than 5 after application of the iron oxide slurry to the coating to form a spot on the coating, air dry for four hours, and wash with soap and water until the stain can no longer be removed.

The present invention also relates to a method for improving the stain resistance of a substrate with the coating composition described herein compared to the same coating composition that does not contain self-crosslinking core-shell particles. The method includes applying the coating composition described herein to at least a portion of the substrate. The coating composition can be applied in liquid form and dried, for example, under temperature conditions ranging from -10°C to 50°C.

Coating composition formulation involves the process of selecting and mixing the appropriate coating ingredients in the correct proportions to provide a paint with particular processing and handling properties, as well as a final dry paint film with the desired properties. The coating composition can be applied to the substrate by conventional application methods such as brushing, rolling, and spraying methods such as air spray, pneumatic spray, airless spray, high volume low pressure spray and pneumatic airless spray.

Suitable substrates include, but are not limited to, structural substrates such as metallic or non-metallic substrates including: concrete, plaster, cement board, medium density fibreboard (MDF) and particle board (chipboard), gypsum board, wood, stone, metal, plastics, wallpapers, textiles, stucco, fiberglass, ceramics, etc., which can be pre-primed with a water-based or organic solvent-based primer. The structural substrate may be wood, concrete and/or plaster exposed to external conditions. It has been found that when applied to a substrate and dried to form a coating thereon, the dried coating containing both the self-crosslinking core-shell particles and the hydrophobic additive imparts improved stain resistance.

The substrate may comprise a base layer located under the coating formed from the coating composition. The base layer may be a weathered coating layer. As used herein, a weathered coating layer is defined as a coating layer that has been exposed to the outside environment for an extended period of time, such as at least 3 months, at least 6 months, at least 1 year, at least 2 years. or at least 5 years. As such, a coating formed from a coating composition that is applied over a weathered coating layer can be defined as a finishing coating layer (eg, a coating layer over a weathered coating layer after a predetermined period of time has elapsed).

Examples

The following examples are presented to demonstrate the general principles of the invention. The invention should not be construed as being limited to the specific examples presented. All parts and percentages in the examples are by weight unless otherwise indicated.

Example 1

Obtaining latex with particles with a core-shell structure

Part A: First, polyurethane was prepared by loading the following components in order into a four-necked round bottom flask equipped with a thermocouple, mechanical stirrer and condenser: 113 grams of butyl methacrylate, 4 grams of trimethylol propane, 8.7 grams of hydroxyethyl methacrylate (HEMA), 0.7 grams of 2.6 -di-tert-butyl 4-methylphenol, 91 grams FOMREZ 66-56 (a saturated linear hydroxy-terminated polyester polyol commercially available from Chemtura Corporation (Philadelphia, PA)), 91 grams POLYMEG 2000 (commercially available from Lyondell Basell Industries Holdings, B.V. (Rotterdam, The Netherlands)) and 35 grams of dimethylpropionic acid (DMPA). The mixture was heated to 50°C and kept for 15 minutes. After the mixture was heated, 160 grams of isophorone diisocyanate was charged to the flask over 10 minutes and stirred for 15 minutes. The flask was then charged with 8.2 grams of butyl acrylate, 1.3 grams of triethylamine, and 0.34 grams of dibutyltin dilaurate (DBTDL). An immediate exothermic effect was observed. After the exothermic effect subsided, the mixture was heated to 90° C. and kept for 60 minutes. The mixture was then cooled to 70° C. and charged into a flask with 80 grams of butyl methacrylate and 19.8 grams of hexanediol diacrylate. The mixture was kept at 60° C. before being dispersed in water.

Part B: Latex containing polyurethane-acrylic particles with a core-shell structure was obtained by initial loading the following components into a four-necked round-bottom flask equipped with a thermocouple, mechanical stirrer and condenser: 500 grams of deionized water, 26 grams of diacetone acrylamide and 6.5 grams of ethylenediamine . The mixture was heated to 70°C and kept for 2 hours in a layer of N ₂ . After heating the mixture, the flask was charged with 26.0 grams of adipic dihydrazide, 14.4 grams of ammonium hydroxide, 2.2 grams of ethylenediamine, 8.0 grams of AEROSOL OT (commercially available from Cytec Solvay Group (Woodland Park, NJ)) and 450 grams of deionized water and kept at 50°C for 15 minutes. Then 520 grams of the polyurethane obtained in part A was dispersed in the flask for 20 minutes and stirred for another 15 minutes. The flask was loaded with a mixture of 0.5 grams of ammonium persulfate, 1.0 grams of 70% butyl hydroperoxide and 40 grams of deionized water. Thereafter, 1.2 grams of sodium metabisulphite and 40 grams of deionized water were loaded over 30 minutes. After the exothermic effect, the mixture was kept at 60°C for another hour. After cooling to 40°C 0.2 grams FOAMKILL 649 (a non-silicone antifoam commercially available from Crucible Chemical Company (Greenville, SC)), 3.0 grams ACTICIDE MBS (a microbiocide formed from a mixture of 1,2-benzisothiazoline-3 -one and 2-methyl-4-isothiazolin-3-one, commercially available from Thor GmbH (Speyer, Germany)) and 5 grams of deionized water and stirred for another 15 minutes. The solids content of the resulting latex was 36.7%.

Example 2

Obtaining latex with particles with a core-shell structure

Part A: First, polyurethane was prepared by loading the following components in order into a four-necked round-bottom flask equipped with a thermocouple, mechanical stirrer and condenser: 113 grams of butyl methacrylate, 4 grams of trimethylol propane, 8.7 grams of hydroxyethyl methacrylate (HEMA), 0.7 grams of 2.6 -di-tert-butyl-4-methylphenol, 182 grams of FOMREZ 44-56 (a saturated, linear hydroxy-terminated polyester polyol commercially available from Chemtura Corporation (Philadelphia, PA)), 1.3 grams of triethylamine, and 35 grams of dimethylpropionic acid (DMPA). The mixture was heated to 50°C and kept for 15 minutes. After the mixture was heated, the flask was charged with 160 grams of isophorone diisocyanate over 10 minutes and stirred for 15 minutes. The flask was then charged with 8.2 grams of butyl methacrylate and 0.34 grams of dibutyltin dilaurate (DBTDL). An immediate exothermic effect was observed. After the decay of the exothermic effect, the mixture was heated to 90°C and kept for 60 minutes. The mixture was then cooled to 70° C. and the flask was charged with 113 grams of methyl methacrylate and 19.8 grams of hexanediol diacrylate. The mixture was kept at 60° C. before being dispersed in water.

Part B: Latex containing polyurethane-acrylic particles with a core-shell structure was obtained by initial loading the following components into a four-necked round-bottom flask equipped with a thermocouple, mechanical stirrer and condenser: 500 grams of deionized water, 26 grams of diacetone acrylamide and 6.5 grams of ethylenediamine . The mixture was heated to 70°C and kept for 2 hours in a layer of N ₂ . After heating the mixture, the flask was charged with 1.5 grams of ethylenediamine, 26.0 grams of adipine dihydrazide, 14.4 grams of ammonium hydroxide, 8 grams of AEROSOL OT (commercially available from Cytec Solvay Group (Woodland Park, NJ)) and 450 grams of deionized water and kept at 50°C for 15 minutes. Then 520 grams of the polyurethane obtained in part A was dispersed in the flask for 20 minutes and stirred for another 15 minutes. The flask was loaded with a mixture of 0.5 grams of ammonium persulfate, 0.1 grams of 1% divalent ammonium sulfate (FAS), 1.0 grams of 70% butyl hydroperoxide and 40 grams of deionized water. Thereafter, 1.2 grams of sodium metabisulphite, 3 grams of ammonium hydroxide, and 40 grams of deionized water were loaded over 30 minutes. After the exothermic effect, the mixture was kept at 60°C for another hour. After cooling to 40°C 0.2 grams FOAMKILL 649 (a non-silicone antifoam commercially available from Crucible Chemical Company (Greenville, SC)), 3.0 grams ACTICIDE MBS (a microbiocide formed from a mixture of 1,2-benzisothiazoline-3 -one and 2-methyl-4-isothiazolin-3-one, commercially available from Thor GmbH (Speyer, Germany)) and 5 grams of deionized water and stirred for another 15 minutes. The solids content of the resulting latex was 35.7%.

Example 3

Obtaining latex with particles with a core-shell structure

Part A: Polyurethane was first prepared by loading the following components in order into a four-necked round-bottom flask equipped with a thermocouple, mechanical stirrer and condenser: 113 grams of butyl acrylate, 4 grams of trimethylol propane, 8.7 grams of hydroxyethyl methacrylate (HEMA), 0.7 grams of 2.6 -di-tert-butyl-4-methylphenol, 182 grams of FOMREZ 44-56 (a hydroxy-terminated saturated linear polyester polyol commercially available from Chemtura Corporation (Philadelphia, PA)), 1.3 grams of triethylamine, and 35 grams of dimethylpropionic acid (DMPA). The mixture was heated to 50°C and kept for 15 minutes. After the mixture was heated, 160 grams of isophorone diisocyanate was charged to the flask over 10 minutes and stirred for 15 minutes. The flask was then charged with 8.2 grams of butyl acrylate and 0.34 grams of dibutyltin dilaurate (DBTDL). An immediate exothermic effect was observed. After the exothermic effect subsided, the mixture was heated to 90° C. and held for 60 minutes. The mixture was then cooled to 70° C. and the flask was charged with 113 grams of butyl acrylate and 19.8 grams of hexanediol diacrylate. The mixture was kept at 60° C. before being dispersed in water.

Part B: Latex containing polyurethane-acrylic particles with a core-shell structure was obtained by initial loading the following components into a four-necked round-bottom flask equipped with a thermocouple, mechanical stirrer and condenser: 500 grams of deionized water, 26 grams of diacetone acrylamide and 6.5 grams of ethylenediamine . The mixture was heated to 70°C and kept for 2 hours in a layer of N ₂ . After the mixture was heated, the flask was charged with 1.7 grams of ethylenediamine, 26.0 grams of adipindihydrazide, 14.4 grams of ammonium hydroxide, 8 grams of AEROSOL OT (commercially available from Cytec Solvay Group (Woodland Park, NJ)) and 450 grams of deionized water and kept at 50°C for 15 minutes. Then 520 grams of the polyurethane obtained in part A was dispersed in the flask for 20 minutes and stirred for another 15 minutes. The flask was loaded with a mixture of 0.5 grams of ammonium persulfate, 0.1 grams of 1% divalent ammonium sulfate (FAS), 1.0 grams of 70% butyl hydroperoxide and 40 grams of deionized water. Thereafter, 1.2 grams of sodium metabisulphite, 3 grams of ammonium hydroxide, and 40 grams of deionized water were loaded over 30 minutes. After the exothermic effect, the mixture was kept at 60°C for another hour. After cooling to 40°C 0.2 grams FOAMKILL 649 (a non-silicone antifoam commercially available from Crucible Chemical Company (Greenville, SC)), 3.0 grams ACTICIDE MBS (a microbiocide formed from a mixture of 1,2-benzisothiazoline-3 -one and 2-methyl-4-isothiazolin-3-one, commercially available from Thor GmbH (Speyer, Germany)) and 5 grams of deionized water and stirred for another 15 minutes. The solids content of the resulting latex was 35.7%.

Examples 4-7

Preparation of Coating Compositions

To form the coating compositions of Examples 4-6 and Comparative Example 7, the components from Table 1 were added to one vessel using the following addition order with medium agitation using a conventional high-lift paddle.

Tap water and NUOSEPT 95 were added, followed by stirring for about 5 minutes. ROZONE 2000 was then added, followed by stirring for 5 minutes. Then ethylene glycol was added. Thereafter, a mixed sample of SILRES BS 1306 was added, followed by stirring for at least 20 minutes. Next, the latex from one of examples 1-3 (for examples 4-6) or RHOPLEX 585 latex (for comparative example 7) was added, and then FOAMSTAR MO 2140. Then ACTICIDE OTW 45 was added. After that, the composition was mixed for at least another 10 minutes. MICHEMLUBE 693 was then added. The composition was then stirred for another 10 minutes until complete to form the coating composition.

Table 1 Position name Example 4 Example 5 Example 6 Comparative Example 7 Weight (lb) Weight (lb) Weight (lb) Weight (lb) tap water 75.94 75.94 75.94 75.94 NUOSEPT 95 ¹ 0.25 0.25 0.25 0.25 ^ROZONE20002 0.12 0.12 0.12 0.12 ethylene glycol 0.44 0.44 0.44 0.44 SILRES BS 1306 ³ 0.51 0.51 0.51 0.51 Latex example 1 20.87 - - - Latex from example 2 - 20.87 - - Latex from example 3 - - 20.87 - RHOPLEX 585 ⁴ - - - 20.87 ACTICIDE OTW 45 ⁵ 0.17 0.17 0.17 0.17 MICHEMLUBE 693 ⁶ 1.67 1.67 1.67 1.67 FOAMASTER MO 2140 ⁷ 0.02 0.02 0.02 0.02

¹ Preservative commercially available from Ashland (Covington, Kentucky)

² Biocide commercially available from Rohm and Haas (Philadelphia, PA)

³ Silicone resin modified polysiloxane emulsion commercially available from Wacker Chemie AG (Munich, Germany)

⁴ Acrylic binder commercially available from Dow Chemical Company (Midland, MI)

⁵ Microbiocide commercially available from Thor GmbH (Speyer, Germany)

⁶ Wax emulsion commercially available from Michelman Inc. (Cincinnati, Ohio)

⁷ Defoamer commercially available from BASF (Ludwigshafen, Germany)

The coating compositions of Examples 4-6 and Comparative Example 7 were then applied with a foam brush to a previously applied and weathered basecoat system that had been applied to Pressure Treated Wood (PTL). The basecoat/PTL system was weathered horizontally in Springdale PA for at least one year prior to applying the clear coat compositions of Examples 4-6 and Comparative Example 7. A clear acrylic oil blotch was applied to the basecoat/PTL system. . The coating compositions of Examples 4-6 and Comparative Example 7 were applied to a clear acrylic oil spot to form the test substrate. Colorimetric values for coated substrates were measured and stored using a MacBeth Color-eye spectrophotometer.

The substrates were tested for stain resistance according to the following stain test method. Using a foam brush, a uniform layer of Mapico iron oxide slurry was applied to the substrates. Mapico iron oxide slurry was prepared using 250 grams of tap water, 2 drops of TAMOL 731 surfactant (commercially available from Rohm and Haas Company (Philadelphia, PA)) and 125 grams of Mapico 641 brown iron oxide pigment (commercially available from Rockwood Pigments). ) (Beltsville, MD)) was mixed using a Cowles mixer for 15 minutes at high speed. The substrates coated with the Mapico iron oxide slurry were allowed to dry under normal laboratory conditions for 4 hours. The Mapico iron oxide slurry coated substrates were washed with warm water and DAWN PROFESSIONAL dishwashing detergent (commercially available from Proctor and Gamble (Cincinnati, Ohio)), wiping with a damp soapy sieve cloth to remove stains to the maximum. DAWN PROFESSIONAL Dishwashing Detergent bottle states that it contains (CAS number): water (7732-18-5), sodium alkyl sulfate (68585-47-7), ethanol (64-17-5), sulfate sodium alkyl ethoxylate (68585-34-2); and amine oxide (70592-80-2). The washed substrates were then rinsed and left to dry. Colorimetric values were again taken from substrates treated with the above stain test method using a MacBeth Color-eye spectrophotometer, and the ΔE value between a coated substrate and the same coated substrate tested with the stain test method was determined. . ΔE values for substrates coated with the coating compositions of Examples 4-6 and Comparative Example 7 are shown in Table 2 below.

table 2 Substrate ∆E Coated from Example 4 4.5 Coated from Example 5 5.2 Coated from example 6 6.4 Coated from Comparative Example 7 7.6

The substrate coated with the coating composition of Examples 4-6 had a lower ΔE compared to the substrate coated with the coating composition of Comparative Example 7, indicating that the coating obtained from the coating composition of Examples 4-6 gave improved stain resistance compared to the coating obtained from the coating composition of Comparative Example 7.

The present invention also includes the subject matter of the following items:

Claim 1. A coating composition comprising: an aqueous dispersion of self-crosslinking core-shell particles, wherein the core-shell particles comprise (1) a polymer core at least partially encapsulated by (2) a polymer shell containing urethane bonds, keto- and/or aldo-functional groups and hydrazide functional groups, wherein the polymer core is covalently bonded to at least a portion of the polymer shell, and a hydrophobic additive containing a wax and/or silicon-containing compound, the hydrophobic additive being non-reactive with the polymer core and the polymer shell.

Item 2. The coating composition according to claim 1, characterized in that the polymer core contains an additive polymer derived from ethylenically unsaturated monomers.

Item 3. A coating composition according to claim 2, wherein the ethylenically unsaturated monomers comprise (meth)acrylate monomer, vinyl monomer, and/or a combination thereof.

Item 4. Composition for coating according to any one of paragraphs. 1-3, characterized in that the polymer shell contains a water-dispersible group.

Item 5. Composition for coating according to any one of paragraphs. 1-4, characterized in that particles with a core-shell structure are formed from a mixture of reagents containing: (a) ethylenically unsaturated polyurethane prepolymers with an isocyanate functional group; (b) a Michael addition reaction product of ethylenically unsaturated monomers containing a keto and/or aldo functional group and a compound containing at least two amino groups; (c) a hydrazide functional component; and (d) ethylenically unsaturated monomers.

Item 6. Composition for coating according to any one of paragraphs. 1-5, characterized in that the polymer core does not contain keto and/or aldo functional groups at all.

Item 7. Composition for coating according to any one of paragraphs. 1-6, additionally containing an additive to prevent the formation of mold.

Item 8. Composition for coating according to any one of paragraphs. 1-7, characterized in that the polymer core has a Tg from 10°C to 30°C.

Item 9. Composition for coating according to any one of paragraphs. 1-8, characterized in that the hydrophobic additive is 1-35 mass percent based on the total mass of solids of the coating composition.

Item 10. Composition for coating according to any one of paragraphs. 1-9, characterized in that when the coating composition is applied to a substrate and cured to form a coating, the cured coating has a ΔE of not more than 10 after applying the iron oxide slurry to the coating to form a spot on the coating, air drying for four hours, and washing with soap and water until the stain can no longer be removed.

Item 11. Substrate with at least partially coated, formed from the coating composition according to any one of paragraphs. 1-10.

Item 12. The substrate according to claim 11, characterized in that the substrate contains wood, concrete and/or plaster.

Item 13. A substrate according to claim 11 or 12, further comprising a base coat layer located under the coating formed from the coating composition.

Claim 14. The substrate of claim 13, wherein the coating layer formed from the coating composition is a refinish coating layer and the basecoat layer is a weathered coating layer.

Item 15. A method of improving the resistance of a substrate to staining, comprising: obtaining a coating composition by: obtaining an aqueous dispersion of self-crosslinking particles with a core-shell structure, and particles with a core-shell structure contain (1) a polymer core at least partially encapsulated ( 2) a polymeric shell containing urethane linkages, keto and/or aldo-functional groups and hydrazide functional groups, wherein the polymeric core is covalently bonded to at least a part of the polymeric shell; and adding a hydrophobic additive containing wax and/or silicon-containing compound to the aqueous dispersion; and applying the coating composition to the substrate.

Item 16. The method according to p. 15, characterized in that the coating composition is a coating composition according to any one of paragraphs. 1-10.

Item 17. The method according to p. 15 or 16, characterized in that the substrate is a substrate according to any one of paragraphs. 11-14.

Clause 18. The method according to any one of paragraphs. 15-17 further comprising applying the coating composition over the basecoat layer, wherein the basecoat layer is a weathered coating layer.

While specific embodiments of the present invention have been described above for purposes of illustration, those skilled in the art will appreciate that numerous variations of the elements of the present invention may be made without departing from the invention as defined in the appended claims.

Claims (26)

1. A stain resistant coating composition comprising an aqueous dispersion of self-crosslinking core-shell particles, wherein the core-shell particles comprise (1) a polymeric core at least partially encapsulated by (2) a polymeric shell containing urethane linkages, keto and/or aldo functional groups and hydrazide functional groups, wherein the polymer core is covalently bonded to at least a portion of the polymer shell, and a hydrophobic additive containing a wax and/or a silicon-containing compound, the hydrophobic additive being non-reactive with the polymer core and the polymer shell. 2. Coating composition according to claim 1, characterized in that the polymer core contains an additive polymer derived from ethylenically unsaturated monomers. 3. Coating composition according to claim 2, characterized in that the ethylenically unsaturated monomers contain (meth)acrylate monomer, vinyl monomer and/or a combination thereof. 4. Coating composition according to claim 1, characterized in that the polymer shell contains a water-dispersible group. 5. The coating composition according to claim 1, characterized in that the particles with a core-shell structure are formed from a mixture of reagents containing: (a) ethylenically unsaturated polyurethane prepolymers with an isocyanate functional group; (b) a Michael addition reaction product of ethylenically unsaturated monomers containing a keto and/or aldo functional group and a compound containing at least two amino groups; (c) a hydrazide functional component; and (d) ethylenically unsaturated monomers. 6. Coating composition according to claim 1, characterized in that the polymer core is completely free of keto and/or aldo functional groups. 7. The coating composition of claim. 1, further containing an additive to prevent the formation of mold. 8. Coating composition according to claim 1, characterized in that the polymeric core has a Tg of 10°C to 30°C. 9. The coating composition according to claim. 1, characterized in that the hydrophobic additive is 1-35 weight percent based on the total weight of solids of the coating composition. 10. The coating composition according to claim 1, characterized in that when the coating composition is applied to a substrate and cured to form a coating, the cured coating has ΔΕ of not more than 10 after applying the iron oxide slurry to the coating to form a spot on the coating, drying on air for four hours and washing with soap and water until the stain can no longer be removed. 11. An at least partially coated substrate formed from the coating composition of claim 1. 12. The substrate according to claim 11, characterized in that the polymer core contains an additive polymer derived from ethylenically unsaturated monomers, the ethylenically unsaturated monomers containing a (meth)acrylate monomer and/or a vinyl monomer. 13. The substrate according to claim 11, characterized in that the substrate contains wood, concrete and/or plaster. 14. The substrate of claim. 11, further comprising a base coat layer located under the coating formed from the coating composition. 15. The substrate of claim 14, wherein the coating layer formed from the coating composition is a refinish coating layer and the basecoat layer is a weathered coating layer. 16. A method for improving the stain resistance of a substrate, comprising preparation of the coating composition by obtaining an aqueous dispersion of self-crosslinking particles with a core-shell structure, and particles with a core-shell structure contain (1) a polymer core, at least partially encapsulated by (2) a polymer shell containing urethane bonds, keto and/or aldo functional groups and hydrazide functional groups, wherein the polymer core is covalently bonded to at least a portion of the polymer shell; and adding a hydrophobic additive containing wax and/or silicon-containing compound to the aqueous dispersion; and applying the coating composition to the substrate. 17. Method according to claim 16, characterized in that the substrate contains wood, concrete and/or plaster. 18. The method of claim 16, comprising applying the coating composition over a basecoat layer, wherein the basecoat layer is a weathered coating layer. 19. The method of claim. 16, characterized in that the polymer core contains an additive polymer derived from ethylenically unsaturated monomers, and ethylenically unsaturated monomers contain (meth)acrylate monomer, vinyl monomer and/or a combination thereof. 20. The method according to claim 16, characterized in that when the coating composition is applied to a substrate and cured to form a coating, the cured coating has ΔΕ of not more than 10 after applying the iron oxide slurry to the coating to form a spot on the coating, drying in air in four hours and washing with soap and water until the stain can no longer be removed.