HK1174650B - Waterborne coating compositions, related methods and coated substrates - Google Patents

Description

Aqueous coating compositions, related methods, and coated substrates

Technical Field

The present invention relates to coating compositions. More particularly, the present invention relates to aqueous coating compositions. The invention also relates to a method of using the above composition and to a substrate coated with a coating deposited from the above composition.

Background

Coating compositions, often referred to as 1-K compositions, in which all components are stored together in a single container, are desirable in many instances, for example, for convenience to the end user. One of the properties that the above coating compositions should have is storage stability. In other words, the viscosity of the composition should not increase significantly over time to the point where the composition is no longer suitable for convenient use in depositing a coating.

In many cases, it is desirable to use a liquid coating composition, which is carried in water as opposed to an organic solvent. This desire generally stems primarily from environmental concerns over the release of Volatile Organic Compounds (VOCs) during the coating process.

In some cases, such as when the coating composition is applied to articles such as consumer electronics devices, including laptop computers, personal digital assistants, cellular telephones, and the like, which are often used by humans, it is important that the coating prepared from the composition be particularly resistant to certain oils and acids, such as oleic acid, which can stimulate human perspiration. Furthermore, it is important that the coatings described above are particularly resistant to alcohol, solvents and abrasion, as well as capable of an aesthetically pleasing high gloss appearance, including the absence of "blemishes," when any of a variety of spray equipment and conditions are used.

The present invention has been made in view of the above.

Disclosure of Invention

In certain aspects, the present invention relates to coating compositions, such as 1-K waterborne coating compositions. These coating compositions comprise a continuous phase as well as a dispersed phase. The continuous phase comprises water. The dispersed phase comprises a microgel having an average particle size greater than 50 nanometers. The microgel is formed from reactants comprising, or in some cases consisting essentially of, (i) no more than 5 weight percent, based on the total weight of the reactants, of a polyethylenically unsaturated compound, and (ii) a plurality of monoethylenically unsaturated compounds selected to provide a copolymer having a calculated Tg greater than 100 ℃ and comprising a cycloaliphatic (meth) acrylate.

In other aspects, the present invention relates to aqueous coating compositions comprising a continuous phase and a dispersed phase. The continuous phase comprises water. The dispersed phase comprises a microgel. The microgel comprises the reaction product of reactants comprising, or in some cases consisting essentially of: (i) a multi-ethylenically unsaturated compound, and (ii) a plurality of monoethylenically unsaturated compounds selected to provide a copolymer having a calculated Tg of greater than 100 ℃ and comprising a cycloaliphatic (meth) acrylate. Additionally, the microgel has an average particle size of greater than 50 nanometers and is present in the coating composition in an amount of at least 50 percent by weight, based on the total weight of resin solids in the composition.

In addition, the present invention relates to methods of using the above-described coating compositions and substrates at least partially coated with a coating deposited from the above-described coating compositions.

Detailed Description

For purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by 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 reported significant digits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

Moreover, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges between the recited minimum value of 1 and the recited maximum value of 10, i.e., all sub-ranges having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.

In this application, the use of the singular includes the plural, and the plural encompasses the singular, unless specifically stated otherwise. In addition, in this application, the use of "or" means "and/or" unless specifically stated otherwise, but "and/or" may be explicitly used in certain instances.

As previously mentioned, certain embodiments of the present invention are directed to coating compositions, such as 1-K waterborne coating compositions. As used herein, the term "1-K" refers to a coating composition in which all composition components are stored together in a single container and is storage stable, which means that the viscosity of the composition does not increase significantly over time to the point where the composition is no longer suitable for convenient use in depositing a coating. Indeed, in certain embodiments, the coating composition is storage stable at 140 ° f when stored in sealed containers for up to 1 year.

As used herein, the term "aqueous" refers to a coating composition for which the solvent or carrier fluid, i.e., the continuous phase, comprises mostly or predominantly water. For example, in certain embodiments, the continuous phase is at least 70 weight percent, and in some cases at least 80 weight percent, of water, based on the total weight of the continuous phase. In addition, certain of the coating compositions of the present invention are "low voc coating compositions". As used herein, the term "low voc composition" means that the composition contains no more than five (5) pounds of voc per gallon of the coating composition. As used herein, the term "volatile organic compound" refers to a compound that has at least one carbon atom and is released from the composition during drying and/or curing of the composition. Examples of "volatile organic compounds" suitable for use in the present invention include, but are not limited to, alcohols, benzene, toluene, chloroform, and cyclohexane. A specific example of a suitable volatile organic compound is diethylene glycol monoethyl ether.

As previously mentioned, the coating composition of the present invention comprises a dispersed phase comprising a microgel. As used herein, and as understood by those skilled in the art, the term "microgel" refers to gelled, i.e., internally crosslinked, polymer particles, which are typically in the micron range or smaller in diameter. The microgel particles present in the coating compositions of the invention are typically generally uniform, i.e., non-core shell.

In certain embodiments of the invention, the microgel is uniformly small in size, i.e., less than 20% of the gel particles after polymerization have a particle size greater than 5 microns, or in some cases greater than 1 micron. In certain embodiments, the microgel has an average particle size of no more than 1 micron, such as no more than 900 nanometers, no more than 800 nanometers, no more than 500 nanometers, no more than 400 nanometers, or, in some cases, no more than 350 nanometers. Further, in certain embodiments, the microgel has an average particle size of at least 1 nanometer, such as greater than 5 nanometers, greater than 10 nanometers, greater than 50 nanometers, or, in some cases, greater than 100 nanometers. The gel particle diameter may be measured by photon correlation spectroscopy, as described in international standard ISO 13321. The average particle size values reported herein were measured by photon correlation spectroscopy using a Malvern Zetasizer 3000HSa according to the following method. Approximately 10mL of ultrafiltered deionized water and 1 drop of the homogeneous test sample were added to a clean 20mL vial and then mixed. The tube was washed and filled with ultrafiltration deionized water and about 3-6 drops of the diluted sample were added thereto. Once any air bubbles were removed, the tube was placed in a Zetasizer 3000HSa using a Correlatrontrol window (100-. Particle size measurements were then made with a Zetasizer 3000 HSa.

In certain embodiments, the microgel is the primary source, or in some cases, essentially the only source, of resin solids in the coating compositions of the invention. As a result, in certain embodiments, the microgel is present in the coating composition of the invention in an amount of at least 50 percent by weight, such as at least 70 percent by weight, at least 80 percent by weight, at least 90 percent by weight, or, in some cases, at least 92 percent by weight, based on the total weight of resin solids in the coating composition. Indeed, it has been surprisingly found that the higher Tg microgels described herein, even when used as essentially the only source of resin solids for the coating compositions of the present invention, can coalesce to form cured films having a pleasing "defect-free" high gloss appearance (even when coated using a variety of spray equipment and conditions) and surprisingly good chemical and stain resistance, such as ethanol, isopropanol, lactic acid, oleic acid, and methyl ethyl ketone resistance.

In certain embodiments, the coating compositions of the present invention are substantially, or in some cases completely, free of any other polymeric particles, such as polymeric particles having an average diameter in the range of 1 to 50 nanometers. In this specification, "substantially free" means that the other polymer particles are present in the composition in an amount of less than 1 wt%, such as no more than 0.5 wt% or no more than 0.1 wt%, based on the total weight of resin solids in the coating composition. By "completely free" is meant that no other polymer particles are present in the composition at all.

The microgel present in the coating composition of the invention is formed from reactants comprising a polyethylenically unsaturated compound. As used herein, the term "polyethylenically unsaturated compound" refers to a compound containing more than one ethylenically unsaturated group per moleculeSuch as monomers and/or oligomers. As can be appreciated, the presence of the polyethylenically unsaturated compound is necessary for the formation of the internally crosslinked resin particles, i.e., the microgels. Specific examples of suitable multi-ethylenically unsaturated monomers include ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, triallylisocyanurate, diallyl phthalate and divinylbenzene. Also suitable are hydrophobic monomers, such as silicone-modified (meth) acrylates, fluorinated (meth) acrylates, and fluorinated ethylenes. Specific examples of the above materials include, but are not limited to, Ebecryl from UCB, Belgium^TM350 (Si Di-acrylic ester) and Ebecryl^TM1360 (silicon hexaacrylate) and, available from Siltech Corporation, Toronto, Anda, CanadaSilicone acrylate, 1H, 6H-perfluoro-1, 6-hexanediol diacrylate, and 1H, 6H-perfluoro-1, 6-hexanediol dimethacrylate, and the like.

In certain embodiments, a relatively low level of crosslinking is required to keep the microgel particle size within a useful range. Thus, in certain embodiments, the polyethylenically unsaturated compound comprises predominantly di (meth) acrylate, and the di (meth) acrylate is used in relatively small amounts, as described below. As used herein, "primarily" means that greater than 50%, in some cases at least 60%, at least 70%, at least 80%, or, in some cases, at least 90% of the polyethylenically unsaturated compound is di (meth) acrylate, based on the total weight of the polyethylenically unsaturated compound. As used herein, "(meth) acrylate" and similar terms are meant to encompass both acrylates and methacrylates.

In certain embodiments, the polyethylenically unsaturated compound is present in an amount of no more than 5 weight percent, such as no more than 4 weight percent, no more than 3 weight percent, no more than 2.5 weight percent, or in some cases no more than 2 weight percent, based on the total weight of the reactants used to form the microgel. In certain embodiments, the polyethylenically unsaturated compound is present in an amount of at least 0.1 weight percent, such as at least 0.5 weight percent, or in some cases at least 1 weight percent, based on the total weight of the reactants used to form the microgel.

In certain embodiments, the microgel present in the coating compositions of the invention is the reaction product of reactants comprising a plurality of monoethylenically unsaturated compounds. As used herein, the term "monoethylenically unsaturated compounds" means that the reactant comprises two or more compounds, such as monomers and/or oligomers, that comprise one ethylenically unsaturated group per molecule.

Further, in certain embodiments, the monoethylenically unsaturated compounds are selected to provide copolymers having a calculated glass transition temperature ("Tg") greater than 100 ℃, such as at least 105 ℃. In certain embodiments, the monoethylenically unsaturated compounds are selected to provide copolymers having a calculated Tg of no more than 120 ℃, such as no more than 115 ℃, or in some cases no more than 110 ℃. This means that The theoretical copolymer formed from The selected monoethylenically unsaturated monomers has a calculated Tg within The listed ranges in their selected amounts when calculated as described in "The chemistry Organic Film Formers", D.H.Solomon, J.Wiley & Sons, New York, 1967, page 29.

Furthermore, as indicated previously, the various monoethylenically unsaturated compounds used in the preparation of the microgels present in the coating compositions of the present invention include cycloaliphatic (meth) acrylates. In certain embodiments, the cycloaliphatic (meth) acrylate has a calculated Tg of at least 95 ℃, such as at least 100 ℃. Cycloaliphatic (meth) acrylate monomers include, but are not limited to, trimethylcyclohexyl acrylate, t-butylcyclohexyl acrylate, dicyclopentadienyl (meth) acrylate, trimethylcyclohexyl methacrylate (calculated Tg of 98 ℃), cyclohexyl methacrylate (calculated Tg of 83 ℃), isobornyl methacrylate (calculated Tg of 110 ℃), 2-ethylhexyl methacrylate, tetrahydrofurfuryl methacrylate, 3, 5-trimethylcyclohexyl methacrylate (calculated Tg of 125 ℃), and/or 4-t-butylcyclohexyl methacrylate, and the like. As used herein, if the calculated Tg of a (meth) acrylate is said to be a certain value, it means that the calculated Tg of the theoretical homopolymer formed from that (meth) acrylate when calculated as described in the above-mentioned Solomon has the recited value.

In certain embodiments, the cycloaliphatic (meth) acrylate is used in an amount of up to 30 weight percent, such as up to 20 weight percent or up to 15 weight percent, based on the total weight of monoethylenically unsaturated compounds used in the preparation of the microgel used in the coating composition of the invention. In certain embodiments, the cycloaliphatic (meth) acrylate is used in an amount of at least 1 weight percent, such as at least 5 weight percent or at least 10 weight percent, based on the total weight of monoethylenically unsaturated compounds used in the preparation of the microgel used in the coating compositions of the present invention.

As noted, other monoethylenically unsaturated monomers are used to prepare the microgels used in the coating compositions of the present invention. For example, in certain embodiments, the reactant further comprises a vinyl aromatic compound, such as a vinyl aromatic monomer, and in certain embodiments, the reactant comprises a compound having a calculated Tg of at least 100 ℃. Specific examples of vinyl aromatic compounds are styrene (which has a calculated Tg of 100 ℃), alpha-methylstyrene (which has a calculated Tg of 168 ℃), vinyltoluene, p-methylstyrene, ethylvinylbenzene, vinylnaphthalene, vinylxylene, alpha-methylstyrene dimer (meth) acrylate, pentafluorostyrene, and the like.

In certain embodiments, the vinyl aromatic compound is used in an amount of up to 40 weight percent, such as up to 30 weight percent, based on the total weight of monoethylenically unsaturated compounds used to prepare the microgels used in the coating compositions of the present invention. In certain embodiments, the vinyl aromatic compound is used in an amount of at least 1 weight percent, such as at least 10 weight percent or at least 20 weight percent, based on the total weight of monoethylenically unsaturated compounds used in the preparation of the microgel used in the coating composition of the present invention.

In certain embodiments, the reactants used to prepare the microgels used in the coating compositions of the invention also comprise alkyl (meth) acrylates, and in certain embodiments, compounds having a calculated Tg of at least 100 ℃. A specific example of the alkyl (meth) acrylate is C₁-C₂₄Alkyl (meth) acrylates, such as methyl (meth) acrylate (having a calculated Tg of 105 ℃), propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, and mixtures thereof.

Other monoethylenically unsaturated compounds suitable for use in preparing the microgel present in the coating composition of the invention include, for example, nitriles, such as acrylonitrile and/or methacrylonitrile.

In certain embodiments, the alkyl (meth) acrylate is used in an amount of up to 80 weight percent, such as up to 70 weight percent, based on the total weight of monoethylenically unsaturated compounds used to prepare the microgels used in the coating compositions of the present invention. In certain embodiments, the alkyl (meth) acrylate is used in an amount of at least 50 weight percent, such as at least 60 weight percent, based on the total weight of monoethylenically unsaturated compounds used to prepare the microgel used in the coating composition of the present invention.

In certain embodiments, the microgel for use in the coating compositions of the invention is formed from reactants comprising a plurality of monoethylenically unsaturated monomers comprising, or in some cases consisting essentially of (a) from 10 to 40 percent by weight, such as from 20 to 30 percent by weight, based on the total weight of the monoethylenically unsaturated monomer compounds, of a vinyl aromatic monomer having a calculated Tg of at least 100 ℃, such as styrene, (b) from 50 to 80 percent by weight, such as from 60 to 70 percent by weight, based on the total weight of the monoethylenically unsaturated monomer compounds, of an alkyl (meth) acrylate having a calculated Tg of at least 100 ℃, such as methyl methacrylate, and (c) from 1 to 40 percent by weight, such as from 10 to 20 percent by weight, based on the total weight of the monoethylenically unsaturated monomer compounds, of a cycloaliphatic (meth) acrylate having a calculated Tg of at least 95 ℃, such as isobornyl methacrylate.

In certain embodiments, the plurality of monoethylenically unsaturated compounds is present in an amount of at least 90 percent by weight, such as at least 95 percent by weight, based on the total weight of the reactants used to form the microgel.

In addition to the above compounds, other reactants may be used to form the microgel present in the coating composition of the invention. For example, in certain embodiments, the reactants may further comprise a water-soluble ethylenically unsaturated compound. As used herein, the term "water-soluble ethylenically unsaturated compound" refers to a compound having a solubility in water of at least 7% by weight at a temperature of 25 ℃. Examples of water-soluble ethylenically unsaturated compounds include ethylenically unsaturated ionic compounds and ethylenically unsaturated water-soluble nonionic compounds, such as those disclosed in U.S. patent 7,091,275 at column 3, line 64 to column 5, line 44, the portions of which are incorporated herein by reference. In certain embodiments, the water-soluble ethylenically unsaturated compound comprises an acid-containing compound, such as a compound comprising a carboxylic acid group, such as methacrylic acid (having a calculated Tg of 228℃.) and acrylic acid (having a calculated Tg of 106℃.), and the like.

In certain embodiments, the water-soluble ethylenically unsaturated compound is used in an amount of up to 2% by weight, based on the total weight of monoethylenically unsaturated compounds used to prepare the microgels used in the coating compositions of the present invention. In certain embodiments, the water-soluble ethylenically unsaturated compound contains acid groups and is used in an amount sufficient to provide the microgel with from 0.01 to 0.1 milliequivalents of acid per gram of polymer solids.

In certain embodiments, the microgel may comprise functional groups suitable for reaction with an external complementary crosslinker (which is an optional component of the coating composition of the invention) and may be bound onto the microgel by using reactants comprising ethylenically unsaturated compounds containing selected functional groups. Complementary reactive groups include, for example: (a) acetoacetic ester-aldehyde, (b) acetoacetic ester-amine, (c) amine-aldehyde, (d) amine-anhydride, (e) amine-isocyanate, (f) amine-epoxy, (g) aldehyde-hydrazide, (i) acid-epoxy, (j) acid-carbodiimide, (k) acid-chloromethyl, (j) acid-chloromethane, (m) acid-anhydride, (n) acid-aziridine, (o) epoxy-thiol, and (p) isocyanate-alcohol, and the like.

In certain embodiments, the ethylenically unsaturated compound containing additional functional groups comprises an acrylic monomer comprising aldehyde and/or ketone functional groups. Acrylic monomers comprising aldehyde and/or ketone functional groups, as used herein, refers to acrylic monomers comprising at least one group represented by the following structure:

wherein R is a monovalent hydrocarbon group and R' is hydrogen or a monovalent hydrocarbon group. Specific examples of suitable such monomers include, but are not limited to, those listed in U.S. Pat. No. 4,786,676 column 3, lines 39-56, U.S. Pat. No. 2 column 29-56, U.S. Pat. No. 4,959,428 column 2, and U.S. Pat. No. 5,447,970 column 2, line 59 to column 3, line 15, the portions of which are incorporated herein by reference. The above monomers may be used alone or in a mixture.

In these embodiments, the external crosslinker may comprise at least two functional groups reactive with a carbonyl group, such as any nitrogen-containing compound having at least two amine nitrogen atoms reactive with a carbonyl group. The above-mentioned crosslinking agent may be aliphatic or aromatic, polymeric or non-polymeric, and may be used singly, in combination of two or more. Non-limiting examples of suitable crosslinking agents include those containing at least two hydrazide groups, i.e., NH-NH₂A compound of the group. Specific examples of the above compounds are given in U.S. Pat. No. 7,115,682, column 10, line 12 to column 11, line 26, the description of which is incorporated herein by referenceAnd is incorporated by reference in part herein. In certain embodiments, the crosslinking agent is present in the composition in an amount such that the functional groups of the acrylic polymer reactive with carbonyl functional groups (e.g., hydrazide groups) are present in an amount of 0.02 to 5 equivalents, such as 0.1 to 3 equivalents, or, in some cases, 0.5 to 2 equivalents, of carbonyl groups per equivalent of carbonyl groups contained in the microgel.

In certain embodiments, the ethylenically unsaturated compound containing additional functional groups is used in an amount of up to 3% by weight, based on the total weight of the monoethylenically unsaturated compounds used to prepare the microgels used in the coating compositions of the present invention.

In certain embodiments, the reactants used to form the microgel are substantially free, or in some cases, completely free of (i) any hydrophobic polymers such as hydrophobic polyesters, (ii) nitrile functional compounds, (iii) amide functional compounds, and/or (iv) carbamate functional compounds. As used herein, the term "substantially free of, when used to refer to a material that is substantially free of, means that such material, if present, is incidental impurities. In other words, the material does not affect the coating composition properties. As used herein, the term "completely free" means that the material is not present at all in the composition.

Microgels are often prepared in the form of emulsions comprising the above-described microgels in an aqueous continuous phase. The emulsion can be prepared by, for example, latex emulsion polymerization of the polymerizable reactants described above. In certain embodiments, a surfactant may be added to the aqueous continuous phase to stabilize or prevent agglomeration or clumping of the monomer droplets, particularly during polymerization.

The surfactant may be present in any concentration that stabilizes the emulsion. The surfactant may be present in an amount of at least 0.001 wt%, such as at least 0.005 wt%, at least 0.01 wt%, or at least 0.05 wt%, based on the total weight of the emulsion. The surfactant can be present in an amount of up to 10 wt%, such as up to 7.5 wt%, up to 5 wt%, or in some cases up to 3 wt%, based on the total weight of the emulsion. The amount of surfactant used is determined by the amount needed to stabilize the emulsion.

The surfactant may be an anionic, cationic, reactive or nonionic surfactant, i.e., a dispersant, or a compatible mixture thereof, such as a mixture of anionic and nonionic surfactants. Suitable cationic dispersants that may be used include, but are not limited to, pyridinium lauryl chloride, cetyl dimethyl amine acetate, and alkyl dimethyl benzyl ammonium chloride, wherein the alkyl group has from 8 to 18 carbon atoms.

Suitable anionic dispersants include, but are not limited to, alkali metal fatty alcohol sulfates such as sodium lauryl sulfate (Dupont C or QC, available from Du Pont), and the like, arylalkyl sulfonates such as potassium isopropylbenzene sulfonate, and the like, alkali metal alkyl sulfosuccinates such as sodium octyl sulfosuccinate, and the like, and alkali metal arylalkyl polyethoxyethanol sulfates or sulfonates such as sodium octylphenoxy polyethoxyethyl sulfate or ammonium nonylphenoxy polyethoxyethyl sulfate having from 1 to 50 ethylene oxide units, mixed long chain alcohol sodium sulfates available from Du Pont under the name Dupont WN, octyl sodium sulfates available from Alcolac, Ltd under the name Sipex OLS, sodium tridecyl ether sulfates (Sipex EST), sodium lauryl ether sulfates (Sipon ES), magnesium lauryl sulfates (Sipon LM), ammonium lauryl sulfates (Sipon L-22), diethanolamino lauryl sulfate (Sipon LD), sodium dodecylbenzenesulfonateDS), sodium lauryl ether sulfate, magnesium lauryl ether sulfate, sodium lauryl ether-8 sulfate, mixtures of lauryl ether-8 magnesium sulfate sold by Cognis under the name Texapon ASV, sodium lauryl ether sulfate (C12-1470/30) (2.2EO), sold by Cognis under the name Sipon AOS 225 or Texapon N702 Paste, ammonium lauryl ether sulfate (C hexapon sulfate_12-1470/30) (3EO), sold by Cognis under the name SiponLea 370, and/or (C)_12-14) Ammonium alkyl polyoxyethylether (9EO) sulfate sold under the name Rhodapex AB/20 by Rhodia Chimie.

Reactive surfactants are generally suitable for use in combination with one or more of the above anionic surfactants. Examples of the above-mentioned reactive emulsifier are a reactive anionic surfactant, a sulfosuccinate-reactive anionic surfactant, and an alkenyl succinate-reactive anionic surfactant. Examples of commercially available sulfosuccinate reactive anionic surfactants are LATEMUL S-120, S-120A, S-180 and S-180A (trade name, product of Kao Corp.) and ELEMINOL JS-2 (trade name, product of Sanyo Chemical Industries, Ltd.). An example of a commercially available alkenyl succinate reactive anionic surfactant is LATEMUL ASK (trade name, product of Kao Corp.). Another suitable reactive surfactant is C_3-5Aliphatic unsaturated sulfoalkyl carboxylate (containing 1 to 4 carbon atoms) ester surfactants such as sulfoalkyl (meth) acrylate ester surfactants such as sulfoethyl 2- (meth) acrylate sodium salt and 3-sulfopropyl (meth) acrylate ammonium salt, and aliphatic unsaturated dicarboxylic acid alkylsulfuryldiphenyl ester surfactants such as sulfopropyl maleate sodium salt, sulfopropyl maleate polyoxyethylene alkyl ester sodium salt and sulfopropyl fumarate polyoxyethylene alkyl ester ammonium salt, polyethylene glycol maleate alkylphenol ether sulfate, dihydroxyethyl phthalate (meth) acrylate sulfate, 1-allyloxy-3-alkylphenoxy-2-polyethylene oxide sulfate (trade name: ADEKA soap reach-10N, products of ADEKA corp.), polyethylene oxide alkylalkenyl phenol sulfate (trade name: AQUALON, DAI-ICHI KOGYO SEIYAKU co., ltd. products), and ADEKA-REASOAP SR-10 (products of ADEKA corp., EO mol = 10), SR-20 (products of EO mol =20, ADEKA corp., products), and SR-30 (products of EO mol =30, ADEKA corp.).

Suitable nonionic surfactants include, but are not limited to, alkylphenoxypolyethoxyethanol, which has an alkyl group of from about 7 to 18 carbon atoms and from about 6 to about 60 ethyleneoxy units, for example heptylphenoxypolyethoxyethanol, ethylene oxide derivatives of long chain carboxylic acids or mixtures of acids such as lauric acid, myristic acid, palmitic acid, oleic acid, etc., such as those of tall oil containing from 6 to 60 ethyleneoxy units, ethylene oxide condensates of long chain alcohols containing from 6 to 60 ethyleneoxy units, such as octanol, decanol, lauryl alcohol, or cetyl alcohol; ethylene oxide condensates of long chain or branched amines containing 6 to 60 ethyleneoxy units, such as dodecylamine, hexadecylamine, and octadecylamine; and block copolymers of ethylene oxide segments combined with one or more hydrophobic propylene oxide segments. High molecular weight polymers such as hydroxyethyl cellulose, methyl cellulose, polyacrylic acid, polyvinyl alcohol, and the like can be used as emulsion stabilizers.

Free radical initiators are often used in latex emulsion polymerization processes. Any suitable free radical initiator may be used. Suitable free radical initiators include, but are not limited to, thermal initiators, photoinitiators, and redox initiators, all of which may be further classified as either water soluble initiators or water insoluble initiators.

Examples of thermal initiators include, but are not limited to, azo compounds, peroxides, and persulfates. Suitable persulfates include, but are not limited to, sodium persulfate and ammonium persulfate. Non-limiting examples of redox initiators that may be included are persulfate-sulfite systems, and systems in which a thermal initiator is used in combination with a suitable metal ion such as iron or copper.

Suitable azo compounds include, but are not limited to, water-insoluble azo compounds such as 1-1' -azobiscyclohexanecarbonitrile, 2-2' -azobisisobutyronitrile, 2-2' -azobis (2-methylbutyronitrile), 2-2' -azobis (propionitrile), 2-2' -azobis (2, 4-dimethylvaleronitrile), 2-2' -azobis (valeronitrile), 2- (carbamoylazo) -isobutyronitrile, and mixtures thereof, and water-soluble azo compounds such as azobis (di-tert-alkyl) compounds including, but not limited to, 4-4' -azobis (4-cyanovaleric acid), 2-2' -azobis (2-methylpropionamidine) dihydrochloride, 2' -azobis [ 2-methyl-N- (2-hydroxyethyl) propionyl) dihydrochloride Amine ], 4 '-azobis (4-cyanovaleric acid), 2' -azobis (N, N '-dimethyleneisobutyramidine), 2' -azobis (2-amidinopropane) dihydrochloride, 2 '-azobis (N, N' -dimethyleneisobutyramidine) dihydrochloride, and mixtures thereof.

Suitable peroxides include, but are not limited to, hydrogen peroxide, methyl ethyl ketone peroxide, benzoyl peroxide, di-t-butyl peroxide, di-t-amyl peroxide, cumene peroxide, diacyl peroxide, decanol peroxide, lauroyl peroxide, peroxydicarbonate, peroxyester, dialkyl peroxide, hydroperoxide, peroxyketal, and mixtures thereof.

When the microgel is formed from ionic reactants such as the acid functional monomers described above, the emulsion comprising the microgel, as described above, may also comprise a neutralizing agent. In such cases, the neutralizing agent is often a base. Suitable bases include inorganic as well as organic bases. Suitable inorganic bases include the full range of hydroxides, carbonates, bicarbonates, and acetates of bases or alkali metals. Suitable organic bases include ammonia, primary/secondary/tertiary amines, diamines, and triamines. The amount of neutralizing agent required is generally determined on a molar basis based on the ionic monomer units of polymerization of the neutralizing agent with the microgel. In certain embodiments, the polymerized ionic monomer units are at least 50%, at least 80%, or in some cases at least 90% neutralized.

The examples herein demonstrate suitable conditions for preparing emulsions comprising microgels described herein, typically prepared by latex polymerization of a polymerization-enabling reactant in an aqueous continuous phase which may include one or more of the surfactants and/or free radical initiators described above.

In certain embodiments, the latex emulsion of the microgel in the aqueous continuous phase is prepared by a seed latex emulsion polymerization process. In such a process, a portion of the reactants are polymerized using a portion of the free radical initiator to form polymer seeds dispersed in the continuous phase. Thereafter, the remainder of the initiator is added and the remainder of the reactants are polymerized in the presence of the dispersed polymer seeds to form a latex emulsion of the microgel. If ionic reactants are used, a neutralizing agent may be added to neutralize at least a portion of the ionic groups. Such neutralization may be carried out at elevated temperatures, such as 50-80 ℃, or it may be carried out after the emulsion has cooled to about room temperature, i.e., 25-30 ℃.

The coating composition of the present invention may comprise other components. However, in certain embodiments, the coating compositions of the present invention are substantially free, or in some cases completely free, of any chromium compounds.

In certain embodiments, the coating compositions of the present invention further comprise a colorant. As used herein, the term "colorant" refers to any substance that imparts color and/or other opacity and/or other visual effect to the composition. The colorant can be added to the coating in any suitable form, such as discrete particles, dispersions, solutions, and/or flakes. A single colorant or a mixture of two or more colorants can be used in the coating composition of the present invention.

Examples of colorants include pigments, dyes, and tints, such as those used in the paint industry and/or listed by the Dry Color Manufacturers Association (DCMA), as well as special effect compositions. Colorants can include, for example, finely divided solid powders that are insoluble but wettable under the conditions of use. The colorant may be organic or inorganic and may be agglomerated or non-agglomerated. Colorants can be incorporated into the coating by utilizing a grind vehicle, such as an acrylic grind vehicle, the use of which is well known to those skilled in the art.

Examples of pigments and/or pigment components include, but are not limited to, carbazole dioxazine primary pigments, azo, monoazo, disazo, naphthol AS, salt forms (lakes), benzimidazolones, condensates, metal complexes, isoindolinones, isoindolines, and polycyclic phthalocyanines, quinacridones, perylenes, diketopyrrolopyrroles, thioindigo, anthraquinones, indanthrones, anthraquinone pyrimidines, flavanthrones, pyranthrone dyes, anthanthrones, dioxazines, triarylcarboniums, quinophthalone pigments, diketopyrrolopyrrole reds ("DPPBO reds"), titanium dioxide, carbon black, and mixtures thereof. The terms "pigment" and "coloring filler" may be used interchangeably.

Examples of dyes include, but are not limited to, those based on solvents and/or water such as phthalocyanine green or blue, iron oxide, bismuth vanadate, anthraquinone, perylene, aluminum, and quinacridone.

Examples of coloring agents include, but are not limited to, pigments dispersed in an aqueous-based or water-miscible vehicle, such as AQUA-CHEM 896, commercially available from Degussa, inc., charismacolarts and MAXITONER INDUSTRIAL COLORANTS, commercially available from Accurate Dispersions department of eastman chemical, inc.

As noted above, the colorant may be in the form of a dispersion, including but not limited to a nanoparticle dispersion. Nanoparticle dispersions can include one or more highly dispersed nanoparticle colorants and/or colorant particles that produce a desired visible color and/or opacity and/or visual effect. Nanoparticle dispersions may include colorants such as pigments or dyes having a particle size of less than 150 nanometers, such as less than 70 nanometers, or less than 30 nanometers. The nanoparticles may be prepared by comminuting the starting organic or inorganic pigments with an abrasive having a particle size of less than 0.5 mm. Examples of nanoparticle dispersions and methods for making the same are in U.S. Pat. No. 6,875,800B2, the disclosure of which is incorporated herein by reference. Nanoparticle dispersions can also be prepared by crystallization, precipitation, gas phase agglomeration, and chemical abrasion (i.e., partial dissolution). To minimize re-agglomeration of nanoparticles within the coating, resin-coated nanoparticle dispersions can be used. As used herein, "dispersion of resin-coated nanoparticles" refers to a continuous phase in which are dispersed discrete "composite microparticles" comprising nanoparticles and a coating resin on the nanoparticles. Examples of dispersions of resin-coated nanoparticles and methods for their preparation are in U.S. patent application publication No. 2005-0287348a1, filed 24.6.2004, U.S. provisional patent application publication No. 60/482,167, filed 24.6.24.2003, and U.S. patent application publication No. 11/337,062, filed 20.1.2006, which are also incorporated herein by reference.

Examples of special effect compositions that may be used in the coating compositions of the present invention include pigments and/or compositions that produce appearance effects such as one or more of reflectance, pearlescence, metallic luster, phosphorescence, fluorescence, photochromism, photosensitivity, thermochromism, goniochromism and/or discoloration. Other special effect components may provide other properties that may be perceived, such as opacity or texture. In certain embodiments, special effect components can produce a color shift such that the color of the coating changes when the coating is viewed at different angles. Examples of color effect components are set forth in U.S. Pat. No. 6,894,086, the disclosure of which is incorporated herein by reference. Other color effect components may include transparent coated mica and/or synthetic mica, coated silica, coated alumina, transparent liquid crystal pigments, liquid crystal coatings, and/or any component in which interference results from a refractive index difference within the material rather than from a refractive index difference between the surface of the material and air.

In certain embodiments, a photoactive component and/or a photochromic component that reversibly changes its color when exposed to one or more light sources may be used in the coating compositions of the present invention. The photochromic and/or photosensitive components may be activated by exposure to radiation of a specified wavelength. When the component is excited, the molecular structure changes and the changed structure exhibits a new color that is different from the original color of the component. When the exposure to radiation is removed, the photochromic and/or photosensitive component may return to the ground state, wherein the original color of the component is restored. In certain embodiments, the photochromic and/or photosensitive component can be colorless in a non-excited state and exhibit color in an excited state. Full color changes can manifest within milliseconds to minutes, such as 20 seconds to 60 seconds. Examples of photochromic and/or photosensitive components include photochromic dyes.

In certain embodiments, the photoactive component and/or photochromic component may be associated and/or at least partially linked, such as by covalent bonding, with a polymer and/or polymeric material capable of polymerizing the component. In contrast to some coatings in which the photosensitive component migrates out of the coating and crystallizes into the substrate, according to certain embodiments of the present invention, migration of the photosensitive component and/or photochromic component associated with and/or at least partially associated with the polymer and/or polymerizable component out of the coating is minimized. Examples of photoactive and/or photochromic components and methods for their preparation are given in U.S. patent application 2006-0014099A1, the disclosure of which is incorporated herein by reference.

Typically, the colorant is present in the coating composition in an amount sufficient to impart the desired visual and/or color effect. The colorant may comprise from 1 to 65 weight percent, such as from 3 to 40 weight percent or from 5 to 35 weight percent of the composition of the present invention, wherein the weight percents are based on the total weight of the composition.

In certain embodiments, the coating composition includes one or more effect pigments, such as metallic pigments, e.g., aluminum flakes and copper bronze colored flakes, and mica-like pigments, e.g., metal oxide coated mica. A particular advantage of the coating composition of the present invention is the ability to obtain a metallic coating with a good appearance, i.e., without "blemishes", when any of a variety of spray coating equipment and conditions are employed. Without being bound by theory, it is presently believed that the microgels used as the primary polymeric binder component of the coating composition, or in some cases, as the sole polymeric binder component of the coating composition, have thixotropic properties that promote misting under many conditions while also promoting flake orientation in the deposited coating film. The level of effect pigments present in the compositions of the present invention may vary depending on the other composition components, the desired color, and/or the end use of the coated substrate.

The coating composition of the present invention may further comprise other optional ingredients such as organic solvents, defoamers, pigment dispersants, plasticizers, ultraviolet absorbers, antioxidants, surfactants, and the like. These optional ingredients, when present, are generally present in amounts of up to 30%, typically from 0.1 to 20% by weight, based on the total weight of the coating composition.

The coating composition of the present invention can be prepared by any method known to those of ordinary skill in the art using the above-described components as raw materials. In some cases, the microgel containing emulsion, as described above, is combined with another coating component, such as a colorant, rheology modifier, diluent, and the like, with appropriate agitation. Suitable methods are described in the examples of the present application.

The invention also relates to a method of using the above coating composition. These methods comprise applying the coating composition to the surface of a substrate or article to be coated, coalescing the composition to form a substantially continuous film and then curing the film.

The coating composition of the present invention is suitable for coating any of a variety of substrates, including human and/or animal substrates, such as cutin, fur, skin, teeth, nails, and the like, as well as plants, trees, seeds, agricultural fields such as pastures, arable land, and the like; turf covered areas, such as lawns, golf courses, sports fields, etc., and other land areas such as forests, etc.

Suitable substrates include cellulose-containing materials including paper, paperboard, cardboard, plywood and pressed fiberboard, hardwood, softwood, wood veneer, particleboard, particle board, oriented strand board, and fiberboard. The above-mentioned materials can be made entirely of wood such as pine, oak, maple, mahogany, cherry, and the like. However, in some cases, the material may comprise wood in combination with another material such as a resinous material, i.e., wood/resin composites such as phenolic composites, composites of wood fibers with thermoplastic polymers, and composites of wood reinforced with cement, fiber, or plastic veneers.

Suitable metal substrates include, but are not limited to, foils, sheets, or workpieces constructed from: cold rolled steel, stainless steel, and steel whose surface is treated with any of zinc metal, zinc compounds, and zinc alloys (including electrogalvanized steel, hot-dip galvanized steel, GALVANNEAL steel, and zinc alloy-coated steel), copper, magnesium, and alloys thereof, aluminum alloys, zinc-aluminum alloys such as GALFAN, GALVALUME, aluminum-coated steel, and aluminum alloy-coated steel substrates may also be used. Steel substrates (such as cold rolled steel or any of the above listed steel substrates) coated with a weldable, zinc-rich or iron phosphide-rich organic coating are also suitable for use in the process of the present invention. Such weldable coating compositions are disclosed, for example, in U.S. Pat. Nos. 4,157,924 and 4,186,036. In addition, cold rolled steel is also suitable when pretreated with, for example, a solution selected from the group consisting of metal phosphate solutions, aqueous solutions containing at least one group IIIB or group IVB metal, organophosphate solutions, organophosphonate solutions, and combinations thereof. In addition, suitable metal substrates include silver, gold, and alloys thereof.

Examples of suitable silicate substrates are glass, porcelain (porcelain) and ceramic (ceramic).

Examples of suitable polymeric substrates are polystyrene, polyamides, polyesters, polyethylene, polypropylene, melamine resins, polyacrylates, polyacrylonitrile, polyurethanes, polycarbonates, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone and corresponding copolymers and block copolymers, biodegradable polymers and natural polymers such as gelatin.

Examples of suitable textile substrates are fibers, yarns, threads, knits, fabrics, nonwovens and garments consisting of: polyester, modified polyester, polyester blend fabrics, nylon, cotton blend fabrics, jute fibers, flax fibers, hemp and ramie fibers, viscose fibers, wool, silk, polyamide blend fabrics, polyacrylonitrile, triacetate, acetate, polycarbonate, polypropylene, polyvinyl chloride, polyester microfibers, and glass fiber fabrics.

Examples of suitable leather substrates are roughcast leather (e.g. soft leather from sheep, goat or cow (nappa), and boxer-leather from calf or cow), suede leather (e.g. suede from sheep, goat or calf, and nubuck), split suede leather (e.g. from cow or calf skin), suede leather (buckskin) and sanded leather (nubuk leather); in addition, woollen skins and furs (for example furs with fur) are also known. The leather may be tanned by any conventional tanning method, especially vegetable, mineral, synthetic or combination tanned (e.g. chrome tanned, zirconyl tanned, aluminium tanned or semi-chrome tanned). The leather may also be retanned if desired; for retanning, any tanning agent commonly used for retanning can be used, such as mineral, vegetable or synthetic tanning agents, for example chromium, zirconyl or aluminium derivatives, quebracho, chestnut or wattle bark extracts, aromatic syntans, polyurethanes, (meth) acrylic compounds or (co) polymers of melamine, dicyandiamide and/or urea-formaldehyde resins.

In certain embodiments, the coating compositions of the present invention are suitable for application to "flexible" substrates. As used herein, the term "flexible substrate" refers to a substrate that can be subjected to mechanical stress such as bending or stretching without significant irreversible change. In certain embodiments, the flexible substrate is a compressible substrate. "compressible substrate" and like terms refer to a substrate that is capable of undergoing compressive deformation and returning to substantially the same shape once compressive deformation ceases. The term "compressive deformation" and similar terms mean a mechanical stress that causes an at least temporary reduction in the volume of the substrate in at least one direction. Examples of flexible substrates include non-rigid substrates such as fiberglass woven and nonwoven fabrics, glass woven and nonwoven fabrics, polyester woven and nonwoven fabrics, Thermoplastic Polyurethane (TPU), synthetic leather, natural leather, processed synthetic leather, foams, air, liquid, and/or plasma filled polymeric bladders, polyurethane elastomers, synthetic fabrics, and natural fabrics. Examples of suitable compressible substrates include foam substrates, liquid-filled polymer balloons, air and/or gas-filled polymer balloons, and/or plasma-filled polymer balloons. As used herein, the term "foam substrate" refers to a polymeric or natural material comprising an open cell foam and/or a closed cell foam. As used herein, the term "open cell foam" means that the foam comprises a plurality of interconnected air chambers. As used herein, the term "closed cell foam" means that the foam comprises a series of discrete closed cells. Examples of foam substrates include, but are not limited to, polystyrene foams, polyvinyl acetate and/or copolymers, polyvinyl chloride and/or copolymers, poly (meth) acrylamide foams, polyvinyl chloride foams, polyurethane foams, and polyolefin foams and polyolefin blends. Polyolefin foams include, but are not limited to, polypropylene foams, polyethylene foams, and ethylene vinyl acetate ("EVA") foams. The EVA foam may comprise a flat sheet or plate, or a molded EVA foam, such as a midsole (midsole). Different types of EVA foam may have different types of surface porosity. Molded EVA may comprise a dense surface or "skin" while a flat sheet or plate may exhibit a porous surface. "textiles" may include natural and/or synthetic textiles such as fabrics, vinyl and polyurethane coated fabrics, meshes, nets, ropes, yarns, and the like, and may include, for example, canvas, cotton, polyester, KELVAR, polymer fibers, polyamides such as nylon and the like, polyesters such as polyethylene terephthalate and polybutylene terephthalate and the like, polyolefins such as polyethylene and polypropylene and the like, rayon, polyvinyl polymers such as polyacrylonitrile and the like, other fibrous materials, cellulosic materials, and the like.

The coating composition of the present invention can be applied to the above-mentioned substrate by any of various methods including spraying, brushing, dipping, roll coating, and the like. However, in certain embodiments, the coating compositions of the present invention are applied by spray coating, and thus the compositions generally have a viscosity suitable for spray coating under ambient conditions.

After the coating composition of the present invention is applied to a substrate, the composition is allowed to coalesce to form a substantially continuous film on the substrate. Typically, the film thickness is from 0.01 to 20 mils (about 0.25 to 508 microns), such as from 0.01 to 5 mils (0.25 to 127 microns), or in some cases, from 0.1 to 2 mils (2.54 to 50.8 microns). The coating compositions of the present invention may be pigmented or clear, and may be used alone or in combination as a primer, basecoat, or topcoat.

The coating compositions of the present invention may find particular application in the consumer electronics market in at least some instances. As a result, the present invention also relates to consumer electronic devices such as mobile phones, personal digital assistants, smart phones, personal computers, digital cameras, and the like, which are at least partially coated with a coating deposited from the coating composition of the present invention.

The following examples illustrate the invention and are not to be construed as limiting the invention to their details. In the examples and throughout the specification, all parts and percentages are by weight unless otherwise indicated.

Example 1

Latex emulsions of microgels were prepared using the ingredients listed in table 1.

TABLE 1

Composition (I)		Parts by weight
				Feed #1
Deionized water		398.0
			Rhodapex AB/201		20.69
	Feed #2
			Deionized water		300
Adeka Reasoap SR102		6.0
			Rhodapex AB/201		13.79
Triton N1013		6.0
			Styrene (meth) acrylic acid ester		132
Methacrylic acid methyl ester		349.13
			Isobornyl methacrylate		57.50
Dimethylpropenylglycolic acid		11.4
			Methacrylic acid		9.6
Ethyl carbitol 4		100
				Feed #3
Deionized water		8.56
			Ammonium peroxodisulfate		1.86
	Feed #4
			Partial feed #2		22.7
	Charge #5
			Deionized water		10.0
	Charge #6
			Dimethylethanolamine (DMEA)		3.87
	Charge #7
			Deionized water		20.0

¹Rhodapex AB/20 was produced from Rhodia.

²Adeka Reasoap SR10 is available from Adeka Corporation.

³Triton N101 was produced by Dow Chemical Co.

⁴Ethyl carbitol (diethylene glycol monoethyl ether) was produced from Dow Chemical Co.

Charge #1 was charged to a 2-liter 4-necked flask equipped with a motor-driven stainless steel stirring blade, a water condenser, a nitrogen inlet, and a heating mantle with a thermometer connected through a temperature feedback control device. The flask contents were heated to 80 ℃ and held at this temperature for about 15 minutes for temperature stabilization. During this hold, feed #2 and feed #3 were premixed for 30 minutes. Charge #4 was then added over 5 minutes and held at 80 ℃ for an additional 5 minutes. Feed #3 was added over 5 minutes and held for 30 minutes. After hold, the remainder of feed #2 was added over 180 minutes. Feed #5 was used as a rinse agent for feed # 2. After completion of feed #5, the reaction was held at 80 ℃ for 60 minutes. The batch was cooled to 50-60 ℃ and charge #6 was added over 5 minutes. Feed #7 was used as a rinse for feed # 6. After 60 minutes at 50-60 ℃, the contents were cooled to room temperature. The acrylic latex sample was placed in a 120 ° F heating chamber for 4 weeks and the resin remained as an emulsion. The acrylic microgel had an average particle size of 115 nm, measured as described above at 25 ℃ using a Zetasizer 9000 HS.

Examples 2 to 5

Microgel emulsions with different glass transition temperatures and internal crosslinking were prepared using the method described in example 1. The composition of the resin (% by weight solids) and a characterization of the final resin is shown in table 2.

TABLE 2

¹The solids content was measured at 110 ℃ for 1 hour.

²The average particle size was measured as described above at 25 ℃ using a Zetasizer 9000 HS.

Examples 6 to 9

Coating compositions were prepared using the components and amounts listed in table 3. The amounts are in grams.

TABLE 3

¹Dipropylene glycol methyl ether commercially available from Dow Chemical Company

²Dipropylene glycol n-propyl ether, commercially available from Dow Chemical Company

³Rheology modifier, commercially available from BASF Corporation

⁴Aluminum pigments, commercially available from Silberline Manufacturing co., Inc.

⁵Aluminum paste, commercially available from Eckart America Corporation.

⁶Commercially available from Dow Chemical Company

⁷Colloidal Clay rheology modifiers, commercially available from Southern Clay Products.

Each of the coating compositions of examples 6-9 was prepared for testing in the following manner. This composition was sprayed onto PC-ABS (polycarbonate and acrylonitrile-butadiene-styrene composite) substrates MC 8002-. A flash time of 5 minutes was performed followed by an oven cure of 4 hours at 140 ° F. The film thickness is recorded in table 4.

The cured film was evaluated for chemical resistance, stain resistance, oil acid resistance, hot water resistance, moisture resistance, and abrasion resistance. The results are given in table 4.

TABLE 4

¹Chemical resistance was tested by dipping the Q-tip into the test solution and rubbing the membrane surface back and forth 50 times. If the substrate appeared with less than 50 strokes, the number of strokes was recorded. Otherwise, the surface was examined after 50 rubs and rated for damage.

²Stain resistance was performed by placing a drop of the test solution on the surface of the film and exposing it for 24 hours. After 24 hours, the residual test solution was removed from the surface by rinsing with water. The spots were rated on a scale of 1 to 5, where 1 indicates removal of the coating from the substrate and 5 indicates no mark.

³The oleic acid test was performed by soaking the cured film surface with oleic acid and placing the soaked board horizontally in a humidity chamber at 100% humidity and 100 ° F. After 8 hours of exposure to moisture, the panels were removed and washed with soap and water to remove oleic acid. The overall appearance such as mottle was visually assessed. In addition, color changes from the original were recorded with a Hunter Lab eye. The film was examined for softening with a fingernail.

⁴The hot-water bath test was carried out by dipping the coated PC-ABS panels in water and exposing them to 185 °F for one hour. The luminance of the finish layer and the dynamic color index were measured using a BYK-mac instrument manufactured by BYK-Gardner.

⁵The humidity test involves exposing the coated panels to a humidity chamber set at 100 ° F and 100% relative humidity for 7 days. The luminance of the finish layer and the dynamic color index were measured using a BYK-mac instrument manufactured by BYK-Gardner. Adhesion after humidity application was measured using test method astm d3359 using a paint adhesion test kit commercially available from Paul n. The film was scribed with a pattern of cross-hatching and tape was applied to the scribed area. The tape was then removed and the area was rated on a scale of 0B to 5B, where 0B means that all of the coating was peeled from the substrate and 5B means that no coating was removed.

⁶The Taber abrasion test was performed according to ASTM D4060. CS-17 wheels were used with a total load of 1000g on a 4 "x 4" plate. The number of cycles when the coating was abraded off and reached the substrate was recorded. The weight loss (mg) per cycle was recorded (the lower the value the better the abrasion resistance).

Examples 10 to 14

Latex emulsions with various glass transition temperatures and internal cross-linked microgels were prepared using the method described in example 1. Table 5 shows the composition of the resin (% by weight solids) and the final resin characterization.

TABLE 5

¹The solids content was measured at 110 ℃ for 1 hour.

²Particle size was measured at 25 ℃ using a Zetasizer 9000 HS.

Examples 15 to 19

Coating compositions were prepared using the ingredients and amounts listed in table 6. The amounts are in grams.

TABLE 6

Composition (I)	Example 15	Example 16	Example 17	Example 18	Example 19
						Latex emulsion of example 10	223.05	--	--	--	--
Latex emulsion of example 11	--	223.05	--	--	--
						Latex emulsion of example 12	--	--	223.05	--	--
Latex emulsion of example 13	--	--	--	223.05	--
						Latex emulsion of example 14	--	--	--	--	223.05
Dowanol DPM1	15.15	15.15	15.15	15.15	15.15
						Dowanol DPnP2	10.10	10.10	10.10	10.10	10.10
Deionized water	25.00	25.00	25.00	25.00	25.00
Latekoll D rheology modifier3	3.46	3.46	3.46	3.46	3.46
						Deionized water	24.78	24.78	24.78	24.78	24.78
DMEA amine	0.99	0.99	0.99	0.99	0.99
						Deionized water	14.58	14.58	14.58	14.58	14.58
						SSP-751 aluminium flakes4	--	--	--	--	--
Stapa BG Hydrolan 2192 aluminium5	39.20	39.20	39.20	39.20	39.20
						Aluminum phosphonate passivator	7.72	7.72	7.72	7.72	7.72
Dowanol DPM1	10.11	10.11	10.11	10.11	10.11
						Dowanol DPnP2	5.05	5.05	5.05	5.05	5.05
Butyl cellosolve6	5.05	5.05	5.05	5.05	5.05
Laponite RD rheology modifiers7	1.01	1.01	1.01	1.01	1.01
						Deionized water	50.50	50.50	50.50	50.50	50.50
Total of	435.75	435.75	435.75	435.75	435.75

¹Dipropylene glycol methyl ether, commercially available from Dow Chemical Company

²Dipropylene glycol n-propyl ether, commercially available from Dow Chemical Company

³Rheology modifier, commercially available from BASF Corporation

⁴Aluminum pigments, commercially available from Silberline Manufacturing co., Inc.

⁵Aluminum paste, commercially available from Eckart America Corporation.

⁶Commercially available from Dow Chemical Company

⁷Colloidal Clay rheology modifiers, commercially available from Southern Clay Products.

Each of the coating compositions of examples 15-19 was prepared for testing in the following manner. This composition was sprayed onto PC-ABS (polycarbonate and acrylonitrile-butadiene-styrene composite) substrates MC 8002-. A flash time of 5 minutes was performed followed by an oven cure of 4 hours at 140 ° F. The film thicknesses are recorded in table 7.

The cured film needles were evaluated for chemical resistance, stain resistance, oil acid resistance, hot water resistance, moisture resistance, and abrasion resistance. The results are given in table 7.

TABLE 7

¹Chemical resistance was tested by dipping the Q-tip into the test solution and rubbing the membrane surface back and forth 50 times. If the substrate appeared with less than 50 strokes, the number of strokes was recorded. Otherwise, the surface was examined after 50 rubs and rated for damage.

²Stain resistance was performed by placing a drop of the test solution on the surface of the film and exposing it for 24 hours. After 24 hours, the residual test solution was removed from the surface by rinsing with water. The spots were rated on a scale of 1 to 5, where 1 indicates removal of the coating from the substrate and 5 indicates no mark.

³The oleic acid test was performed by soaking the cured film surface with oleic acid and placing the soaked board horizontally in a humidity chamber at 100% humidity and 100 ° F. After 8 hours of exposure to moisture, the panels were removed and washed with soap and water to remove oleic acid. VisionThe overall appearance such as mottle was assessed. In addition, color changes from the original were recorded with a Hunter Lab eye. The film was examined for softening with a fingernail.

⁴The hot water bath test was performed by dipping the coated PC-ABS panels in water and exposing them to 185 ° F for one hour. The luminance of the finish layer and the dynamic color index were measured using a BYK-mac instrument manufactured by BYK-Gardner.

⁵The humidity test involves exposing the coated panels to a humidity chamber set at 100 ° F and 100% relative humidity for 7 days. The luminance of the finish layer and the dynamic color index were measured using a BYK-mac instrument manufactured by BYK-Gardner. Adhesion after humidity application was measured using test method astm d3359 using a paint adhesion test kit commercially available from Paul n. The film was scribed with a pattern of cross-hatching and tape was applied to the scribed area. The tape was then removed and the area was rated on a scale of 0B to 5B, where 0B means that all of the coating was peeled from the substrate and 5B means that no coating was removed.

⁶The Taber abrasion test was performed according to ASTM D4060. CS-17 wheels were used with a total load of 1000g on a 4 "x 4" plate. The number of cycles when the coating was abraded off and reached the substrate was recorded. The weight loss (mg) per cycle was recorded (the lower the value the better the abrasion resistance).

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims (19)

1. A coating composition comprising:

(a) a continuous phase comprising water; and

(b) a dispersed phase comprising a microgel having an average particle size from greater than 50 to 900 nanometers and formed from reactants comprising:

(i) not more than 5% by weight, based on the total weight of the reactants, of a polyethylenically unsaturated compound, and

(ii) a plurality of monoethylenically unsaturated compounds selected to provide a copolymer having a calculated Tg of greater than 100 ℃ and comprising a cycloaliphatic (meth) acrylate.

2. The coating composition of claim 1, wherein the microgel has an average particle size of from 80 to 500 nanometers.

3. The coating composition of claim 1, wherein the microgel is present in an amount of at least 50 percent by weight based on the total weight of resin solids in the coating composition.

4. The coating composition of claim 3, wherein the microgel is present in an amount of at least 90 percent by weight based on the total weight of resin solids in the coating composition.

5. The coating composition of claim 1, wherein the calculated Tg is from greater than 100 ℃ to 120 ℃.

6. The coating composition of claim 1, wherein the plurality of monoethylenically unsaturated compounds further comprises a vinyl aromatic monomer having a Tg of greater than 100 ℃ and an alkyl (meth) acrylate having a Tg of greater than 100 ℃.

7. The coating composition of claim 6, wherein the plurality of monoethylenically unsaturated compounds comprise:

(a) 10 to 40% by weight, based on the total weight of monoethylenically unsaturated compounds, of a vinylaromatic monomer with a Tg of greater than 100 ℃,

(b) from 50 to 80% by weight, based on the total weight of the monoethylenically unsaturated compounds, of an alkyl (meth) acrylate having a Tg of greater than 100 ℃, and

(c) from 1 to 20% by weight, based on the total weight of monoethylenically unsaturated compounds, of cycloaliphatic (meth) acrylates having a Tg of greater than 95 ℃.

8. The coating composition of claim 1, wherein the plurality of monoethylenically unsaturated compounds are present in an amount of at least 90 percent by weight, based on the total weight of the reactants used to prepare the microgel.

9. The coating composition of claim 7, wherein the reactants further comprise:

(iii) up to 2% by weight, based on the total weight of the reactants, of a water-soluble ethylenically unsaturated monomer.

10. The coating composition of claim 7, wherein the reactants further comprise:

(iv) up to 3 wt%, based on the total weight of the reactants, of an additional functional group-containing ethylenically unsaturated monomer.

11. An aqueous coating composition comprising:

(a) a continuous phase comprising water; and

(b) a dispersed phase comprising a microgel comprising the reaction product of reactants comprising:

(i) a polyethylenically unsaturated monomer, and

(ii) a plurality of monoethylenically unsaturated compounds selected to provide a copolymer having a calculated Tg of greater than 100 ℃ and comprising a cycloaliphatic (meth) acrylate,

wherein the microgel has an average particle size from greater than 50 to 900 nanometers and is present in an amount of at least 50 percent by weight based on the total weight of resin solids in the composition.

12. The coating composition of claim 11, wherein the microgel has an average particle size of from 80 to 500 nanometers.

13. The coating composition of claim 11, wherein the microgel is present in an amount of at least 90 percent by weight based on the total weight of resin solids in the coating composition.

14. The coating composition of claim 11, wherein the calculated Tg is from greater than 100 ℃ to 120 ℃.

15. The coating composition of claim 11, wherein the plurality of monoethylenically unsaturated compounds further comprise a vinyl aromatic monomer having a Tg of greater than 100 ℃ and an alkyl (meth) acrylate having a Tg of greater than 100 ℃.

16. The coating composition of claim 11, wherein the plurality of monoethylenically unsaturated compounds comprise:

(a) 10 to 40% by weight, based on the total weight of monoethylenically unsaturated compounds, of a vinylaromatic monomer with a Tg of greater than 100 ℃,

(b) from 50 to 80% by weight, based on the total weight of the monoethylenically unsaturated compounds, of an alkyl (meth) acrylate having a Tg of greater than 100 ℃, and

(c) from 1 to 20% by weight, based on the total weight of monoethylenically unsaturated compounds, of cycloaliphatic (meth) acrylates having a Tg of greater than 95 ℃.

17. The coating composition of claim 11, wherein the plurality of monoethylenically unsaturated compounds are present in an amount of at least 90 percent by weight, based on the total weight of the reactants used to prepare the microgel.

18. The coating composition of claim 16, wherein the reactants further comprise:

(iii) up to 2% by weight, based on the total weight of the reactants, of a water-soluble ethylenically unsaturated monomer.

19. The coating composition of claim 16, wherein the reactants further comprise:

(iv) up to 3 wt%, based on the total weight of the reactants, of an ethylenically unsaturated monomer comprising an additional functional group.