A method for applying a coating composition to a substrate using a high transfer efficiency applicator.

Abstract

A method for applying a coating composition to a substrate using a high-transfer-efficiency applicator is disclosed, and a coated article is provided. The high-transfer-efficiency applicator comprises a plurality of nozzles, each configured to apply a stream or stream of droplets of the coating composition to the substrate substantially without atomization, and an infrared emitter. The method includes providing a coating composition for application without overspray to the high-transfer-efficiency applicator, and applying the coating composition by arranging a plurality of lines of the coating composition on the substrate via the plurality of nozzles. The method also includes irradiating the coating composition via the infrared emitter during and / or after application to obtain an irradiated coating composition, thereby forming an overspray-free coating layer on the substrate.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Application No. 63 / 499,141, filed on April 28, 2023, and No. 63 / 571,588, filed on March 29, 2024, the contents of which are incorporated herein by reference.

[0002] (Technical Field) The present disclosure generally relates to a method of applying a coating composition to a substrate using a high - transfer - efficiency applicator to form a coating layer, and more specifically, to such a process that includes selectively controlling the solids content of the coating composition during application to control flow, leveling, and sag while the coating layer is being formed.

Background Art

[0003] Inkjet printing is a non - impact printing process in which droplets of ink are deposited on a substrate, typically paper or fabric, in response to an electronic signal. Digital printing, a specific application of this process, allows for precise adjustment according to individual requirements. The droplets can be ejected onto the substrate by various inkjet application methods, including continuous printing and drop - on - demand printing. In drop - on - demand printing, the energy for ejecting ink droplets can be provided from a thermal resistor, a piezoelectric crystal, an acoustic or a solenoid valve. In these methods, applicators with high transfer efficiency are used.

[0004] In the automotive industry, car bodies are typically covered with a series of finishes, each with a specific function, including electrodeposition coating, a primer, a colored base coat, and a clear top coat that provides additional protection and a glossy finish. Currently, most car bodies are painted in a single color with the base coat applied in a single spray application. Coating is done using a pneumatic spray or rotary device that produces a wide spray of paint droplets with a broad droplet size distribution. This has the advantage of allowing for a uniform and high-quality coating in a relatively short time through an automated process.

[0005] However, this process has many drawbacks. When painting a vehicle in multiple colors, for example, if a second color is used for a pattern like stripes, or if an entire section of the vehicle, such as the roof, is painted in a different color, it is necessary to mask the first coating and run the vehicle through the paint spray process twice to add the second color. After this second painting process, the masking must be removed. This is time-consuming and labor-intensive, and the work is very costly.

[0006] The second drawback of current spray technology is that paint droplets are sprayed in a wide spray pattern with a broad range of droplet sizes. As a result, many droplets do not land on the vehicle, either because they are sprayed near the edges, resulting in overspray onto the substrate, or because the smaller droplets are too weak to reach the vehicle body at all. Such excessive overspray must be removed from the spraying process and safely disposed of, leading to a significant amount of waste and incurring additional costs for waste disposal, cleaning, and disposal.

[0007] Applying coatings using a high-transfer-efficiency applicator can provide a solution for applying two colors to a vehicle and minimizing overspray by generating uniformly sized droplets that can be directed to specific points on the substrate, such as specific locations on the vehicle body. Thus, oversprayed droplets can be minimized or completely eliminated. Furthermore, digital coating can be used to paint patterns or two tones on the vehicle body, either as a digitally printed second color on top of a pre-sprayed base coat of a different color, or directly onto a vehicle substrate that has been primed or clear-coated.

[0008] However, conventional inkjet inks are typically formulated to print on porous substrates such as paper and textiles, where the ink is rapidly absorbed by the substrate, making it easy to dry and handle the substrate immediately after printing. Furthermore, while printed articles have sufficient durability for these applications, such as printed letters and pictures or patterned fabrics, the durability requirements for automotive coatings are far more stringent, both in terms of physical durability, such as resistance to abrasion and chipping, and long-term durability against weathering and lightfastness. Moreover, inkjet inks known in the art are typically formulated to have low viscosity, generally shear-independent, or Newtonian viscosity, typically less than 20 cps. Such viscosity profiles are chosen because the amount of energy available to each nozzle of the printhead for ejecting ink droplets is limited, and to avoid ink thickening that could lead to clogging in the printhead channels (e.g., due to shear).

[0009] In contrast, automotive coatings typically exhibit significant non-Newtonian shear behavior, having extremely high viscosity at low shear to avoid pigment sedimentation and ensure a rapid and uniform coating setup immediately after application, but relatively low viscosity at high shear rates to facilitate spray atomization into sprays and droplets.

[0010] Furthermore, even if current technology is suitable for some horizontal applications, there are still other applications, such as vertical applications, where existing technology would be unacceptable. High-transfer-efficiency applicators require very low viscosity with limited shear thinning behavior, making standard methods for imparting sag resistance to spray-applied coatings unsuitable.

[0011] More specifically, the limitations imposed by zero-overspray applicators (continuous stream) or high-resolution drop-on-demand (i.e., "inkjet" printheads) typically require very low high-shear viscosity. In contrast to spray atomization, viscosity buildup does not occur because solvent evaporation does not occur after the paint is ejected from the applicator and before it hits the substrate. As a result, the coating sags on non-horizontal surfaces. To achieve sufficient sag resistance, it is necessary to incorporate rheological modifiers at a high level such that sag is prevented while flow and leveling are hindered by the yield stress, resulting in coating defects specific to zero-overspray applicators. These defects include visible nozzle line and stripe overlaps. The former is due to incomplete flow and leveling of streams or droplets ejected from adjacent nozzles, resulting in visible lines parallel to the direction of printhead movement. The latter is the result of a second stripe of paint (within the width of the nozzle array) being applied adjacent to a first stripe that was applied earlier. While coalescence can be improved by changing the index (distance between adjacent stripes), high levels of rheological modifiers required to prevent sagging result in visible peaks or valleys at overlapping areas that cannot be eliminated by index optimization. Furthermore, due to the limited particle size in these small nozzle applicators, some rheological modifiers cannot be used due to filter and nozzle clogging. Therefore, opportunities for improvement remain. [Overview of the Initiative]

[0012] A method for preparing coated articles is provided herein. This method is A high transfer efficiency applicator is provided, comprising a plurality of nozzles, each configured to apply a stream or droplet of a coating composition to a substrate substantially without atomization, and an infrared emitter. The present invention provides a coating composition for application to a high-efficiency applicator without overspray, wherein the coating composition exhibits an initial shear viscosity of about 10 to 100 cP and / or an initial solids content of about 5 to about 70% at a shear rate of 1000 / second, and comprises a carrier, a binder present in an amount of 5 to about 70 wt.% (weight percent / mass percent concentration) based on the total weight of the coating composition, and a crosslinking agent present in an amount of about 0.1 to about 25 wt.% based on the total weight of the coating composition. By arranging multiple lines of the coating composition on a substrate via multiple nozzles, the coating composition can be applied using a high-transfer-efficiency applicator. The method includes irradiating the coating composition through an infrared emitter during and / or after application to obtain an irradiated coating composition exhibiting a shear viscosity greater than the initial shear viscosity and / or a solid content greater than the initial solid content.

[0013] Coating compositions and systems for use in this method are also provided together with coated articles prepared using this method.

[0014] This patent or patent application file includes at least one color drawing. A copy of this patent or patent application publication containing the color drawing will be provided by the national office upon request and payment of the required fees.

[0015] The following description of this disclosure is accompanied by the attached drawings, where similar figures indicate similar elements. [Brief explanation of the drawing]

[0016] [Figure 1A]This is a top view of a high-transfer-efficiency applicator for applying a coating composition to a substrate. [Figure 1B] Figure 1A is a side view of an embodiment of a high transfer efficiency applicator, in which the emitter is configured to irradiate the coating composition after application to the substrate. [Figure 1C] This is a side view of an alternative embodiment of the high transfer efficiency applicator shown in Figure 1B, in which the emitter is configured to irradiate the coating composition during application to the substrate. [Figure 2] The emitter is separated from the print head and is a side view of an alternative embodiment of a high-transfer-efficiency applicator that includes multiple nozzles for applying a coating composition to a substrate, irradiating a large print area. [Figure 3A] Figure 2 is a side view of an embodiment of a high-transfer-efficiency applicator, showing an emitter that irradiates the coating composition after printing. [Figure 3B] This is another side view of the high-transfer-efficiency applicator of Figure 3A, showing the emitter irradiated with the coating composition at a different time after printing in Figure 3A. [Figure 4] This plot shows the rheological profile of a coating composition suitable for this embodiment, based on the results of a controlled viscosity sweep. [Figure 5A] This is an explanatory diagram of photographs taken of sample coated articles during the evaluation of the appearance of the coatings prepared in the examples, for evaluating the critical film thickness of exemplary coating compositions prepared at different laydown densities. [Figure 5B] This is an explanatory diagram showing a photograph of another sample coated article taken during the evaluation of the appearance of coatings prepared in the same example as shown in Figure 5A, prepared at different laydown densities. [Figure 6] This figure is based on a series of photographs taken over time during the evaluation of the sagging performance of the coatings prepared in the examples, during vertical storage time after application. [Figure 7] This diagram shows photographs taken at different time points after preparing coating compositions using the same test method as in Figure 6, but at different laydown densities. [Figure 8] Explanatory diagram of a series of photographs taken over time during the evaluation of sag performance using forced heat curing of another coating prepared in an embodiment. [Figure 9A] Diagram of a series of photographs taken for the sag and appearance analysis of an exemplary coating (FIG. 9A) prepared according to this embodiment. [Figure 9B] Diagram of a series of photographs taken for the sag and appearance analysis, analyzed for a set of comparative examples (FIGS. 9B, 9C) without irradiation (FIG. 9B). [Figure 9C] Diagram of a series of photographs taken for the sag and appearance analysis, analyzed for a set of comparative examples (FIGS. 9B, 9C) at different radar down densities (FIG. 9C).

Mode for Carrying Out the Invention

[0017] The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure. Furthermore, it is not bound by the theories presented in the above background art or the following detailed description.

[0018] Generally, the present disclosure provides methods for preparing coatings and coated articles, such as methods for applying a coating composition onto a substrate (e.g., forming a coating thereon), coating compositions useful in such methods, and coated articles prepared by such application methods. The present disclosure further provides devices and systems for practicing such methods and / or utilizing such coating compositions as described.

[0019] For the sake of brevity, well-known prior art relating to compositions, methods, processes, devices, systems, and articles, as well as various parts and components thereof, may be introduced in the embodiments herein at various levels of description or otherwise described. For example, prior art relating to the formation of coating compositions may not be described in detail herein, as the various steps in the manufacture of such compositions are well-known and will be readily understood and assumed by those skilled in the art in view of the embodiments and examples provided herein. Similarly, the steps of various tasks and processes described herein may be incorporated into more comprehensive procedures or processes having additional steps or functionalities that are not otherwise described, for example, because they are well-known and readily understood by those skilled in the art. Such prior art steps may be briefly mentioned or omitted entirely without providing details of the well-known process.

[0020] A method for applying a coating composition to a substrate using a high-transfer-efficiency applicator is provided herein. This method is useful, for example, for preparing coated articles for new manufacturing, repair, or refinishing purposes.

[0021] This method utilizes a high-transfer-efficiency applicator to form a coating layer on a substrate. More specifically, this method involves: A high-transfer-efficiency applicator comprising multiple nozzles, each nozzle configured to apply a stream of coating composition or a stream of droplets to a substrate substantially without atomization, and an infrared emitter, To provide a coating composition for application to a high-transfer-efficiency applicator without overspray, Applying a coating composition with a high-transfer-efficiency applicator by arranging multiple lines of the coating composition on a substrate via multiple nozzles, During and / or after application, the coating composition is irradiated via an infrared emitter, and the irradiated coating composition is applied, thereby forming an overspray-free coating layer on the substrate. Includes.

[0022] Coating compositions for application without overspray (i.e., pre-application) typically exhibit an initial shear viscosity of about 10–100 cP and / or an initial solids content of about 5–70% at a shear rate of 1000 / second. Irradiation coating compositions exhibit a shear viscosity greater than the initial shear viscosity and / or a solids content greater than the initial solids content.

[0023] The steps and components of this method are described below in order.

[0024] High transfer efficiency applicators themselves may be known in the art. For example, in various embodiments, applicators are those described in one or more of the patents or publication numbers US2004 / 0217202A1, US2009 / 0304936A1, US2020 / 0070182A1, US7,824,015B2, US8,091,987B2, or US11,117,160B2, each of which is expressly incorporated herein in whole for use in various non-limiting embodiments. Applicators may alternatively be described as printheads or as comprising one or more printheads.

[0025] This method utilizes an emitter. In certain embodiments, this method utilizes an infrared emitter, i.e., a light source that emits radiation including infrared radiation (for example, as light or heat).

[0026] Infrared (IR) radiation can be understood as radiation that includes electromagnetic waves in the spectral range between visible red light and long-wave microwave radiation (i.e., terahertz radiation). The IR spectrum is described in terms of wavelengths (λ) between 780 nm and 1 mm, which corresponds to a frequency range from 300 GHz to 400 THz.

[0027] In a specific segment of the wavelength that generates heat, the IR spectrum is short-wavelength IR (i.e., near-IR, NIR, or IR-A) from 0.78 microns to 1.5 microns, which corresponds to temperatures of several thousand to several hundred degrees Celsius (°C); Medium waves from 1.5 microns to 3 microns (i.e., medium IR, medium IR, MIR, or IR-B), which correspond to temperatures in the high to mid-100°C range; Long-wave infrared radiation from 3 microns to 1000 microns (1 mm), i.e., far-infrared radiation, FIR, or IR-C, corresponds to temperatures from the mid-100s Celsius to absolute zero. This includes... Generally, the shorter the IR wavelength emitted from the emitter, the higher the temperature and penetration of the irradiation. The emitter can also provide radiation other than the IR spectrum.

[0028] The type of emitter is not limited as long as it can irradiate the coating composition for the purposes intended according to the exemplary embodiments. Such emitters may be lamps or lasers, filaments or diodes, thermal emitters or optical emitters, or combinations thereof. Common examples include infrared light-emitting diodes (LEDs) and their organic versions (OLEDs), blackbody light sources, incandescent lamps, and the like.

[0029] The emitter may be adapted to provide broad-spectrum radiation to the coating composition (e.g., via the use of an irradiant infrared heating lamp), or to provide focused, coherent pulses of narrow-spectrum radiation in single, regular, or periodic bursts, or various combinations thereof (e.g., via the use of a semiconductor laser, or via the use of filters, blockers, etc.). Examples of combinations include the use of two emitters for a particular irradiation method, such as the use of a carbon infrared emitter for passive irradiation and a CO2 or LED laser for narrow-focus irradiation.

[0030] Typically, the emitter is an infrared thermal emitter such as a ceramic or quartz-based FIR emitter, a quartz-tungsten-based MIR emitter, or a quartz-halogen-based NIR emitter. Other emitters are also suitable, as can be understood from the description herein.

[0031] The form of the emitter is not limited and is selected based on the intended use, for example, the position of the emitter relative to the applicator and / or substrate, the equipment being operated, the scale of the coating to be performed, the size of the portion of the coating composition being irradiated, etc. Thus, the emitter may be in the form of a light bulb or lamp, a platen with a flat or curved surface, or it may be packaged with other components such as a circulator, fan, blower, etc.

[0032] The emitter may be fixed in a movable position. In some embodiments, the emitter is coupled to a printhead, which is described in more detail below. In such embodiments, the emitter may be part of an applicator, and may be fixed in a fixed position, stably close to the applicator's printhead, or operably mounted to a robot, etc. In other embodiments, the emitter is movable (e.g., mounted to a robot arm, etc.), and the applicator's printhead is fixed in a fixed position. In such embodiments, a movable print bed or other type of movable support surface is typically used to move the substrate relative to the printhead during the application of the coating composition. The movable emitter may be fixed in a fixed position relative to the printhead or print bed / table, or it may be independently movable instead. Illustrative arrangements of specific embodiments are described in more detail below with reference to the illustrative figures in the drawings.

[0033] In one embodiment, a high-efficiency applicator includes a nozzle defining a nozzle orifice, which may have a nozzle diameter of about 0.00002 m to about 0.0004 m. In another embodiment, the applicator may be fluidly connected to a reservoir configured to contain a coating composition. For example, a high-efficiency applicator may be configured to receive a coating composition from a reservoir and discharge the coating composition onto a substrate through a nozzle orifice to form a coating layer. It should be understood that the ranges for nozzle diameter, viscosity, density, surface tension, and relaxation time may be defined by either the ranges described herein or the ranges known in the art. In various non-limiting embodiments, all values ​​and ranges of values, both integers and decimals, including the aforementioned values, are expressly construed for use herein.

[0034] A high-efficiency applicator can be configured to discharge the coating composition through the nozzle orifice at an impact velocity of approximately 0.2 m / s to approximately 20 m / s. Alternatively, a high-efficiency applicator can be configured to discharge the coating composition through the nozzle orifice at an impact velocity of approximately 0.4 m / s to approximately 10 m / s, or at a value outside these ranges.

[0035] The nozzle orifice can have a nozzle diameter of approximately 0.00004 m to approximately 0.00025 m. The coating composition can be discharged from the high-efficiency applicator as droplets having a particle size of at least 10 microns. Alternatively, the coating composition can be discharged from the high-efficiency applicator in a stream.

[0036] In various embodiments, a high transfer efficiency applicator includes a plurality of nozzles, each of which defines a nozzle orifice. The plurality of nozzles can be arranged linearly relative to each other along a first axis. For example, in various embodiments, the plurality of nozzles includes nozzle A and nozzle B adjacent to nozzle A. Nozzles A and B can be spaced apart from each other in terms of nozzle distance. The high transfer efficiency applicator distance from the substrate can be substantially the same as the nozzle distance. Similarly, it is intended that one, two, three, or more applicators can be used in association with each other. Each applicator may be independently one of those described herein or any known in the art.

[0037] In various embodiments, a high-transfer-efficiency applicator includes approximately 50 nozzles aligned along the Y-axis. However, it should be understood that the applicator may contain any number of nozzles. Each nozzle can operate independently of the others to apply the coating composition to the substrate. During ejection, independent actuators for the nozzles can provide control for the placement of each droplet of the coating composition on the substrate.

[0038] In one embodiment, a plurality of nozzles are arranged spaced apart from one another to form a rectangular array, and the plurality of nozzles can be configured to alternately discharge the coating composition between adjacent nozzles in the rectangular array in order to reduce dripping of the coating composition.

[0039] Various nozzles can be used, as long as they are suitable for the types and properties of application methods described herein, such as high transfer efficiency without atomization and overspray. Examples include the nozzle described in WO2022067350A1, which is incorporated herein by reference.

[0040] Two or more applicators can be combined together, for example, in a printhead assembly. In certain embodiments, such applicators are aligned together such that the y-axis of each applicator is parallel to the y-axis of the other. Furthermore, each nozzle of the applicator can be aligned with respect to the x-axis, which is perpendicular to the y-axis, so that an "array" is formed. One nozzle can be spaced equally apart from other nozzles directly adjacent to it with respect to the x and y axes. This nozzle configuration can be suitable for each applicator to apply the same coating composition to the substrate as the printhead assembly moves along the x-axis. Without being bound by theory, it is considered that equal spacing of nozzles with respect to both the x and y axes will result in uniform application of the same coating composition to the substrate. Uniform application of the same coating composition is considered suitable for single-color application, two-tone application, and similar applications.

[0041] Alternatively, one set of nozzles along the first Y-axis may be spaced closer together with respect to another set of nozzles, relative to the spacing between each nozzle along the Y-axis of a single high-efficiency applicator. This nozzle configuration can be suitable for each high-efficiency applicator to apply different coating compositions to a substrate. Different coating compositions used within the same high-efficiency applicator assembly can be suitable for logos, designs, markings, stripes, camouflage appearances, and the like.

[0042] The nozzles of high-efficiency applicators can have any configuration known in the art, such as linear, concave relative to the substrate, convex relative to the substrate, circular, and so on. Adjusting the nozzle configuration may be necessary to facilitate the cooperation of high-efficiency applicators with substrates having irregular configurations, such as those of vehicles, including mirrors, trim panels, contours, spoilers, etc.

[0043] A high-transfer-efficiency applicator can be configured to blend individual droplets to form a desired color. The high-transfer-efficiency applicator may include nozzles for applying cyan, magenta, yellow, and black coating compositions. The properties of the coating compositions can be modified to facilitate blending. Furthermore, a stirring source, such as air transport or a sonic generator, can be utilized to promote blending of the coating compositions. The stirring source can be coupled to or separated from the high-transfer-efficiency applicator.

[0044] Identifying the appropriate properties of a coating composition for use with a high transfer efficiency applicator can depend on the properties of the high transfer efficiency applicator itself. The properties of the high transfer efficiency applicator may include the nozzle diameter, the impact velocity of the coating composition by the high transfer efficiency applicator, the velocity, the distance of the high transfer efficiency applicator from the substrate, the droplet size of the coating composition by the high transfer efficiency applicator, the firing velocity of the high transfer efficiency applicator, the orientation of the high transfer efficiency applicator relative to the force of gravity, and the relative mobility of the print head of the application with respect to the emitter and / or substrate (or the print bed on which the substrate is placed).

[0045] The method includes the step of providing a coating composition to a high-efficiency applicator. The providing step is not particularly limited and may be known in the art. For example, the providing step may be described as providing all or part of one or more components of the composition, combining these components to form a composition, and providing the finished composition. Alternatively, the providing step may be described as delivering one or more components of the composition, or the composition as a whole, to the high-efficiency applicator by pumping, flowing, moving, or other means. The providing step may be described as a continuous process or a batch process. Similarly, the providing step may include continuous substeps and / or batch substeps. In various embodiments, the providing step is described as pumping the composition into the applicator under pressure. The providing step may be understood by those skilled in the art.

[0046] A coating composition suitable for use in the method provided. The coating composition is particularly suitable for application without overspray and provides a good appearance through proper flow and leveling while maintaining low sag under the conditions described. The coating composition is formulated as a fluid suitable for the ejection requirements of a high transfer efficiency applicator. These and other advantages will be understood in the embodiments and examples provided herein.

[0047] As will be described in more detail below, the coating composition is not particularly limited to its pre-application form. The coating composition may be formulated and used as a one-component (i.e., "1K") composition. Alternatively, the coating composition may be a two-component (i.e., "2K") composition.

[0048] The coating composition may be a water-borne composition or a solvent-borne composition. However, in a specific embodiment, the coating composition is a 1K solvent-borne composition.

[0049] Examples of one-component and two-component compositions are provided below, followed by a further description of the components constituting coating compositions suitable for use in this embodiment.

[0050] In various embodiments, the composition comprises or consists of a resin including acrylic, polyester, or a combination thereof; a melamine crosslinking agent; an optional pigment; an organic solvent; and at least one polyamide wax. For example, the term “essentially consists of” can represent embodiments without resins or polymers not described herein or optionally described herein, crosslinking agents not described herein or optionally described herein, pigments not described herein or optionally described herein, organic solvents not described herein or optionally described herein, and sag control agents and / or rheology control agents not described herein or optionally described herein. The terms “without” or “absent” can describe a composition containing less than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1% by weight of the composition, for example, by weight of the activator. Alternatively, the terms “without” or “absent” can represent a composition containing none of the compound.

[0051] In various embodiments, the composition comprises or consists of a hydroxyl-functionalized resin; an isocyanate crosslinking agent; an optional pigment; and an organic solvent. For example, the term “essentially consists of” can mean an embodiment without a resin or polymer not described herein or optionally described herein, a crosslinking agent not described herein or optionally described herein, a pigment not described herein or optionally described herein, an organic solvent not described herein or optionally described herein, and a sag control agent and / or rheology control agent not described herein or optionally described herein. The terms “without” or “absent” can mean that the composition contains about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1% by weight of the composition, less than, for example, % by weight of the activator. Alternatively, the terms “without” or “absent” can mean that the composition does not contain the compound at all. In various non-limiting embodiments, all integer and decimal values ​​and ranges of values, including the aforementioned values ​​and those in between, are expressly construed herein for use.

[0052] The one-component and two-component compositions exemplified and described above are illustrative examples and represent selectable solvent-mediated coating compositions. However, the coating compositions may be aqueous and may be provided in other forms as described herein.

[0053] Generally, the coating composition comprises a binder, a crosslinking agent, and a carrier solvent (e.g., a solvent, water, etc.), is printable under the methods described herein, and is tolerable for its particular step, except that it is not particularly limited.

[0054] The term “binder” typically refers to the film-forming component of a coating composition. Such binders may include certain polymers, oligomers, or combinations thereof that are often essential for forming a coating with desired properties such as hardness, protection, and adhesion. Additional components such as carriers, pigments, catalysts, rheology modifiers, antioxidants, UV stabilizers and absorbers, leveling agents, defoamers, crater inhibitors, or other conventional additives are typically not included in the term “binder” unless any of these additional components is a film-forming component itself. However, one or more of these additional components may be included in a coating composition as described below.

[0055] The binder is not particularly limited and may comprise any suitable resin known and used in coating compositions of the types presented herein, such as solvent-based base coats, monocoats, etc. For example, the resin may comprise acrylic, polyester, or a combination thereof. Alternatively, the composition and / or the resin itself may contain polyester and not contain acrylic and / or other polymers. The composition and / or the resin itself may contain both acrylic and polyester and not contain other polymers.

[0056] In various embodiments, acrylics include, but are not limited to, (meth)acrylamide, N-substituted (meth)acrylamide, octyl (meth)acrylate, nonylphenol ethoxylate (meth)acrylate, isononyl (meth)acrylate, 1,6-hexanediol (meth)acrylate, isobornyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, β-carboxyethyl (meth)acrylate, isobutyl (meth)acrylate, cycloaliphatic epoxide, α-epoxide, 2-hydroxyethyl (meth)acrylate, (meth)acrylonitrile, maleic anhydride, itaconic acid, isodecyl (meth)acrylate, dodecyl (meth)acrylate, n-butyl (meth)acrylate. (Meth)acrylate, methyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylic acid, N-vinyl caprolactam, stearyl (meth)acrylate, hydroxyfunctional caprolactone ester (meth)acrylate, octodecyl (meth)acrylate, isooctyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxymethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxyisopropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyisobutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and combinations thereof, etc., are reaction products of one or more monomers from these monomers, contain, essentially consist of, or may consist of.

[0057] In other embodiments, the acrylic essentially comprises, or may comprise, one or more of the following: (meth)acrylicated urethane (i.e., urethane (meth)acrylate), (meth)acrylicated epoxy (i.e., epoxy (meth)acrylate), (meth)acrylicated polyester (i.e., polyester (meth)acrylate), (meth)acrylic (meth)acrylic, (meth)acrylicated silicone, (meth)acrylicated amine, (meth)acrylicated amide; (meth)acrylicated polysulfone; (meth)acrylicated polyester, (meth)acrylicated polyether (i.e., polyether (meth)acrylate), vinyl (meth)acrylate, and (meth)acrylicated oil.

[0058] In various embodiments, the polyester is, contains, essentially consists of, or may consist of any polyester known in the art. For example, the polyester may be linear or branched. Useful polyesters include esterification products of aliphatic or aromatic dicarboxylic acids, polyols, diols, aromatic or aliphatic cyclic anhydrides, and cyclic alcohols. Non-limiting examples of suitable cycloaliphatic polycarboxylic acids are tetrahydrophthalic acid, hexahydrophthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, tricyclodecanedicarboxylic acid, endoethylenehexahydrophthalic acid, camphoric acid, cyclohexanetetracarboxylic acid, and cyclobutanetetracarboxylic acid. Cycloliphatic polycarboxylic acids can be used not only in cis form but also in trans form and mixtures of both. Further non-limiting examples of suitable polycarboxylic acids include aromatic and aliphatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, halogenophthalic acid, e.g., tetrachlorophthalic acid or tetrabromophthalic acid, adipic acid, glutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, trimellitic acid, and pyromellitic acid. Combinations of polybasic acids, such as combinations of polycarboxylic acids and cycloaliphatic polycarboxylic acids, are also suitable. Combinations of polyols are also preferred.

[0059] A non-limiting example of a suitable polyester is a branched copolyester polymer. A branched copolyester polymer and a method for producing the same described in US6,861,495B2, which is incorporated herein by reference, may be preferred. Branched structures can be created using monomers having polyfunctional groups such as AxBy(x,y=1~3, independently) type, including those having one carboxyl group and two hydroxyl groups, two carboxyl groups and one hydroxyl group, one carboxyl group and three hydroxyl groups, or three carboxyl groups and one hydroxyl group. Non-limiting examples of such monomers include 2,3-dihydroxypropionic acid, 2,3-dihydroxy2-methylpropionic acid, 2,2-dihydroxypropionic acid, and 2,2-bis(hydroxymethyl)propionic acid.

[0060] Polyesters can conventionally be polymerized from monomer mixtures containing a chain extender selected from the group consisting of hydroxycarboxylic acids, hydroxycarboxylic acid lactones, and combinations thereof, and one or more branched monomers. Some suitable hydroxycarboxylic acids include glycolic acid, lactic acid, 3-hydroxypropionic acid, 3-hydroxybutyric acid, 3-hydroxyvaleric acid, and hydroxypivalic acid. Some suitable lactones include caprolactone, valerolactone, and the corresponding hydroxyvalerolactone lactones (e.g., 3-hydroxypropionic acid, 3-hydroxybutyric acid, 3-hydroxyvaleric acid, and hydroxypivalic acid). In certain embodiments, caprolactone can be utilized. In embodiments, branched copolyester polymers can be produced in a single step by polymerizing a monomer mixture containing a chain extender and a highly branched monomer, or by polymerizing the highly branched monomer first and then the chain extender. It should be understood that branched copolyester polymers can be formed from acrylic cores having the above-mentioned stretched monomers.

[0061] In various embodiments, resins comprising acrylic, polyester, or a combination thereof are used in amounts of about 10 to about 40% by weight, about 15 to about 35% by weight, or about 20 to about 30% by weight, based on the total weight percent of the coating composition.

[0062] The composition typically contains a crosslinking agent. The term "crosslinking agent" refers to a component having a "crosslinkable functional group," which is a functional group located at the molecule of a compound, oligomer, polymer, polymer backbone, pendant from the polymer backbone, terminal on the polymer backbone, or a combination thereof, and these functional groups can crosslink with other crosslinkable functional groups (during the curing step) to produce a coating in the form of a crosslinked structure. Those skilled in the art will recognize that certain crosslinkable functional groups and certain combinations of crosslinkable functional groups are excluded because they cannot crosslink to produce a film that forms a crosslinked structure.

[0063] In some embodiments, the coating composition comprises an isocyanate crosslinking agent, a melamine crosslinking agent, or both.

[0064] The isocyanate crosslinking agent is not particularly limited and may be known in the art. In various embodiments, the isocyanate crosslinking agent is, but is not limited, one or more isocyanates, including, essentially consisting of, or can consist of, one or more isocyanates, such as polyisocyanates having isocyanurate structural units such as isocyanurate of hexamethylene diisocyanate and isocyanurate of isophorone diisocyanate; adducts of two diisocyanates such as hexamethylene diisocyanate and a diol such as ethylene glycol; uretidione of hexamethylene diisocyanate; uretidione of isophorone diisocyanate or isophorone diisocyanate; and adducts of trimethylolpropane and meta-tetramethylxylenediisocyanate, such as aromatic, aliphatic or cycloaliphatic di-, tri- or tetra-isocyanates.

[0065] In various embodiments, isocyanates such as oligomers based on hexamethylene diisocyanate (HDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), or toluidine diisocyanate (TDI), for example, isocyanurates, biuretes, allophanates, and adducts of the aforementioned isocyanates with polyhydric alcohols and mixtures thereof can be used. These can be reacted with polyols such as OH group-containing polyesters, polyethers, acrylates, and polyurethanes, and mixtures thereof, and these polyols may be solvent-based, solvent-free, or water-dilutable. In various embodiments, monofunctional isocyanates are intended for use herein as selected by those skilled in the art. In other embodiments, blocked isocyanates are intended for use herein as selected by those skilled in the art.

[0066] In various embodiments, the isocyanate crosslinking agent is used in an amount of about 3 to about 6, or about 3, 4, 5, or 6 by weight, based on the total weight of the coating composition.

[0067] In various embodiments, an isocyanate crosslinking agent is not used, and a melamine crosslinking agent is used. Alternatively, both an isocyanate crosslinking agent and a melamine crosslinking agent may be used. In various embodiments, this optional crosslinking agent may be, include, essentially consist of, or comprise any melamine crosslinking agent known in the art.

[0068] Melamine resins can be partially or completely etherified with one or more alcohols such as methanol or butanol. A non-limiting example is hexamethoxymethylmelamine. Non-limiting examples of suitable melamine resins include monomeric melamines, polymeric melamine-formaldehyde resins, or combinations thereof. Monomeric melamines include low molecular weight melamines and, on average, have three or more methylol groups etherified with C1-C5 monohydric alcohols such as methanol, n-butanol, and isobutanol per triazine nucleus, with an average degree of condensation up to about 2, and in certain embodiments ranging from about 1.1 to about 1.8, and a mononucleate ratio of at least about 50 weight percent. In contrast, polymeric melamines have an average degree of condensation of about 1.9 or higher. Such suitable monomeric melamines include alkylated melamines such as methylated, butylated, isobutylated melamines, and mixtures thereof. Many of these suitable monomeric melamines are commercially available. For example, Cytec Industries Inc. of West Paterson, New Jersey, supplies monomeric melamines Cymel® 301 (degree of polymerization 1.5, 95% methyl, 5% methylol), Cymel® 350 (degree of polymerization 1.6, 84% methyl, 16% methylol), 303, 325, 327, 370, and XW3106. Suitable polymeric melamines include high amino (partially alkylated, -N, -H) melamine known as Resimene® BMP5503 (molecular weight 690, polydispersity 1.98, 56% butyl, 44% amino), supplied by Solutia Inc., St. Louis, Mo., or Cymel® 1158, supplied by Cytec Industries Inc. Cytec Industries Inc. also supplies Cymel® 1130 @ 80% solids (degree of polymerization 2.5) and Cymel® 1133 (48% methyl, 4% methylol, 48% butyl). In various non-limiting embodiments, all values ​​and ranges of values, both integers and decimals, including the aforementioned values ​​and those in between, are expressly construed herein for use.

[0069] The coating composition may contain one or more crosslinking agents having the same or different crosslinking functional groups. Typical crosslinking functional groups include hydroxyl, thiol, isocyanate, thioisocyanate, acetoacetoxy, carboxyl, primary amine, secondary amine, epoxy, anhydride, ketimine, aldimine, orthoester, orthocarbonate, cyclic amide, or combinations thereof.

[0070] In various embodiments, an optional crosslinking agent, such as a melamine crosslinking agent, is used in amounts of about 0 to about 30, about 5 to about 30, about 12 to about 25, or about 15 to about 20% by weight, based on the total weight percent of the composition. In other embodiments, this amount is about 5 to about 25, about 10 to about 20, or about 10 to about 15% by weight, based on the total weight percent of the composition.

[0071] In an exemplary embodiment, the coating composition comprises a melamine-formaldehyde resin having the trade name Cymel® 303, which is commercially available from Cytech Industries, Inc. in West Patterson, New Jersey.

[0072] Coating compositions are typically suspensions of film-forming components and optionally additives, and therefore generally include a carrier vehicle, such as a solvent or fluid. The carrier vehicle is typically aqueous or solvent-based, i.e., the coating composition is typically an aqueous or solvent-based composition. Formulations of such carrier vehicles are known in the art and will be best understood by considering the examples and description herein.

[0073] In some embodiments, the solvent is an organic solvent. Suitable organic solvents include aromatic hydrocarbons such as toluene and xylene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, and diisobutyl ketone; and esters such as ethyl acetate, n-butyl acetate, and isobutyl acetate. Some specific examples include methanol, ethanol, isopropanol, n-butanol, 2-butanol, tridecyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, 3-butoxy-2-propanol, ethyl 3-ethoxypropionate, butyl glycol, butyl glycol acetate, butanol, dipropylene glycol methyl ether, diethylene glycol monobutyl ether, butyl glycolate, hexane, heptane, octane, toluene, xylene, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, 2-butoxyethyl acetate, amyl acetate, isoamyl acetate, diethylene glycol butyl ether acetate, acetone, xylene, and toluene. However, typically, the coating composition is substantially free of highly volatile solvents, as well as any other type that would interfere with the applicator and application process of the type described herein. In embodiments, the evaporation rate of the solvent may affect the printability of the coating composition.

[0074] In certain embodiments, the coating composition includes water as a carrier.

[0075] Specific cosolvents can be incorporated into coating compositions having increased or decreased evaporation rates, thus providing a handle for selectively adjusting the rheological profile of the composition during and after application to a substrate. This application will be discussed further later.

[0076] In various embodiments, the organic solvent content is greater than about 50 wt.%, or greater than 60 wt.%, or greater than 70 wt.%, or greater than 80 wt.%, or greater than 90 wt.%, based on the total weight of the liquid carriers in the coating composition. In these embodiments or other embodiments, any one solvent or carrier solvent may be present in the coating composition in any suitable amount, for example, about 5 to about 70 wt.%, or for example, about 10 to about 65 wt.%, based on the total weight of the coating composition. The total amount of carriers utilized will depend on the type of composition (i.e., aqueous or solvent-based) and will be understood in consideration of the range of solids content provided herein.

[0077] The coating composition may contain various components such as binders, dyes, rheological modifiers, carriers, catalysts, conventional additives, or combinations thereof. Conventional additives include, but are not limited to, dispersants, antioxidants, UV stabilizers and absorbers, surfactants, wetting agents, leveling agents, defoamers, crater inhibitors, or combinations thereof. In embodiments, the coating composition is suitable for application to a substrate using a high transfer efficiency applicator, based on the fact that the coating composition contains specific components and / or specific components in specific amounts / ratios.

[0078] Any pigment known in the art for use in coating compositions may be used in the coating composition, provided that it is compatible with the other selected components and the applicator used. Non-limiting examples of suitable pigments include effect pigments containing metal oxides, metal hydroxides, and metal flakes, chromates such as lead chromate, sulfides, sulfates, carbonates, carbon black, silica, talc, clay, phthalocyanine blue and green, organic red, organic maroon, pearlescent pigments, other organic pigments and dyes, and combinations thereof. Chromate-free pigments such as barium metaborate, zinc phosphate, aluminum triphosphate, and combinations thereof may also be available, if desired.

[0079] Further non-limiting examples of suitable effect pigments include glossy aluminum flakes, very fine aluminum flakes, medium-grain aluminum flakes, and glossy medium-coarse aluminum flakes; mica flakes coated with titanium dioxide pigment, known as pearl pigment; and combinations thereof. Non-limiting examples of suitable coloring pigments include titanium dioxide, zinc oxide, iron oxide, carbon black, monoazo red toner, red iron oxide, quinacridone maroon, transparent red iron oxide, dioxazine carbazole violet, iron blue, indanthrone blue, chromium titanate, titanium yellow, monoazo permanent orange, ferrite yellow, monoazo benzimidazolone yellow, transparent yellow oxide, isoindoline yellow, tetrachloroisoindoline yellow, anthanthrone orange, lead yellow chromate, phthalocyanine green, quinacridone red, perylene maroon, quinacridone violet, pre-concentrated chromium yellow, thioindigo red, transparent red oxide chip, orange molybdate, orange molybdate red, and combinations thereof.

[0080] As mentioned above, the coating composition may further contain extender pigments. Generally, extender pigments are used in coating compositions to replace more expensive pigments, but extender pigments as intended herein may increase the shear viscosity of the coating composition compared to a coating composition without extender pigments. An increase in the shear viscosity of the coating composition can improve the suitability of the coating composition for application to a substrate using a high-transfer-efficiency applicator. Extender pigments may have a particle size of about 0.01 to about 44 microns. Extender pigments may have a variety of configurations, including but not limited to nodular, plate-like, needle-like, and fibrous forms. Non-limiting examples of suitable extender pigments include whiting, barite, amorphous silica, fumed silica, diatomaceous earth silica, clay, calcium carbonate, phyllosilicate (mica), wollastonite, magnesium silicate (talc), barium sulfate, kaolin, and aluminum silicate. In various non-limiting embodiments, all integer and decimal values ​​and ranges of values, including the aforementioned values ​​and those in between, are expressly construed herein for use.

[0081] The coating composition may contain an amount of extender pigment in wt.% of about 0.1 to about 50, or about 1 to about 20, or about 1 to about 10, based on the total weight of the coating composition. In certain embodiments, the coating composition includes magnesium silicate (talc), barium sulfate, or a combination thereof. In various embodiments, the inclusion of barium sulfate as the extender pigment results in a coating composition having a greater shear viscosity compared to the inclusion of talc as the extender pigment. In various non-limiting embodiments, all values ​​and ranges of values, both integers and decimals, including the aforementioned values ​​and those in between, are expressly construed herein for use.

[0082] In various embodiments, optional pigments are selected from Pigment Yellow 213, PY151, PY93, PY83, Pigment Red 122, PR168, PR254, PR179, Pigment Red 166, Pigment Red 48:2, Pigment Violet 19, Pigment Blue 15:1, Pigment Blue 15:3, Pigment Blue 15:4, Pigment Green 7, Pigment Green 36, Pigment Black 7 or Pigment White 6, and combinations thereof.

[0083] In various embodiments, the coating composition may further contain dyes. Non-limiting examples of suitable dyes include triphenylmethane dyes, anthraquinone dyes, xanthene and related dyes, azo dyes, reactive dyes, phthalocyanine compounds, quinacridone compounds, and fluorescent whitening agents, and combinations thereof. The coating composition may contain dyes in an amount of about 0.01 to about 5, or about 0.05 to about 1, or about 0.05 to about 0.5, wt.%, based on the total weight of the coating composition. In certain embodiments, the coating composition is a 10% black dye solution such as Sol.Orasol Negro RL.

[0084] The coating composition may be substantially dye-free. As used herein, the term “substantially” means that the coating composition may contain a small amount of dye such that the color and / or properties of the coating composition are not affected by the addition of such a small amount of dye that the composition is still considered substantially dye-free. In embodiments, a substantially dye-free coating composition may contain 5 wt.% or less, or 1 wt.% or less, or 0.1 wt.% or less.

[0085] As mentioned above, the coating composition may further contain a catalyst. The coating composition may further contain a catalyst to shorten the curing time and enable curing of the coating composition at a specific temperature.

[0086] Non-limiting examples of suitable catalysts include organometallic salts such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dichloride, dibutyltin dibromide, and zinc naphthenate, triphenylboron, tetraisopropyl titanate, triethanolamine titanate chelate, dibutyltin dioxide, dibutyltin dioctoate, tin octoate, aluminum titanate, aluminum chelate, zirconium chelate, hydrocarbon phosphonium halides, such as ethyltriphenylphosphonium iodide and other phosphonium salts and other catalysts, or combinations thereof. Non-limiting examples of suitable acid catalysts include carboxylic acids, sulfonic acids, phosphoric acid, or combinations thereof. In some embodiments, the acid catalyst may include, for example, acetic acid, formic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, p-toluenesulfonic acid, phosphoric acid, or combinations thereof.

[0087] The coating composition may contain a catalyst in an amount of about 0.01 to about 5, or about 0.05 to about 1, or about 0.05 to about 0.5, wt.%, based on the total weight of the coating composition. In various non-limiting embodiments, all values ​​and ranges of values, both integers and decimals, including the aforementioned values ​​and those in between, are expressly construed herein for use.

[0088] The coating composition may further contain UV stabilizers or antioxidants. Non-limiting examples of such UV stabilizers include UV absorbers, screeners, quenchers, and hindered amine light stabilizers. Antioxidants may also be added to the coating composition. Typical UV stabilizers include benzophenones, triazoles, triazines, benzoates, hindered amines, and mixtures thereof. Blends of hindered amine light stabilizers such as Tinuvin® 328 and Tinuvin® 123 are available, all of which are commercially available under the Tinuvin® brand from Ciba Specialty Chemicals, Inc. in Tarrytown, New York.

[0089] Non-limiting examples of suitable UV absorbers include hydroxyphenylbenzotriazoles, e.g., 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3,5-di-tert.amyl-phenyl)-2H-benzotriazole, 2[2-hydroxy-3,5-di(1,1-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2-hydroxy-3-tert.butyl-5-methylpropionate)-2H-benzotriazole, and polyethylene ether glycol having a weight-average molecular weight of 300, 2-(2-hydroxy-3-tert.butyl-5-isooctylpropionate)-2H-benzotriazole; Hydroxyphenyl s-triazines, e.g., 2-[4-((2,-hydroxy-3-dodecyloxy / tridecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-(2-ethylhexyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(4-octyloxy-2-hydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; Examples of hydroxybenzophenone-based UV absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, and 2-hydroxy-4-dodecyloxybenzophenone.

[0090] Non-limiting examples of suitable hindered amine-based light stabilizers include N-(1,2,2,6,6-pentamethyl-4-piperidinyl)-2-dodecylsuccinimide, N(1-acetyl-2,2,6,6-tetramethyl-4-piperidinyl)-2-dodecylsuccinimide, N-(2-hydroxyethyl)-2,6,6,6-tetramethylpiperidine-4-ol-succinic acid copolymer, 1,3,5-triazine-2,4,6-triamine, N,N'”-[1,2-ethane bis[[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]imino]-3,1-propanediyl]]bis[N,N'”-dibutyl-N',N'”-bis(1,2,2,6,6-penta Methyl-4-piperidinyl), poly-[[6-[1,1,3,3-tetramethylbutyl)amino]-1,3,5-triandine-2,4-diyl][2,2,6,6-tetramethylpiperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]), bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[3,5-bis(1,1-dimethylethyl-4-hydroxyphenyl)methyl]butylpropanediate, Examples include 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro(4,5)decane-2,4-dione and dodecyl / tetradecyl-3-(2,2,4,4-tetramethyl-2l-oxo-7-oxa-3,20-diazaldispiro(5.1.11.2)henicosan-20-yl)propionate.

[0091] Non-limiting examples of suitable antioxidants include tetrakis[methylene(3,5-di-tert-butylhydroxyhydrocinnamate)]methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, tris(2,4-di-tert-butylphenyl)phosphite, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and benzenepropanoic acid, and 3,5-bis(1,1-dimethyl-ethyl)-4-hydroxy-C7-C9 branched alkyl esters. In certain embodiments, the antioxidant includes a hydroperoxide decomposer, such as Sanko®. HCA (9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide), triphenyl phosphate, and other organophosphorus compounds, e.g., TNPP from Irgafos® Ciba Specialty Chemicals, 168 from Irgafos® Ciba Specialty Chemicals, 626 from Ultranox® GE Specialty Chemicals, Mark PEP-6 from Asahi Denka, Mark HP-10 from Asahi Denka, P-EPQ from Irgafos® Ciba Specialty Chemicals, Ethanox 398 from Albemarle, Weston 618 from GE Specialty Chemicals, and Irgafos®. Examples include 12 products from Ciba Specialty Chemicals and Irgaphos (registered trademark), 38 products from Ciba Specialty Chemicals, Ultranox (registered trademark) 641 (GE Specialty Chemicals), and Doverphos (registered trademark) S-9228 from Dover Chemicals.

[0092] The coating composition may further include wetting agents, leveling agents, and flow control agents. Examples include Resiflow® S (polybutyl acrylate), BYK® 320 and 325 (high molecular weight acrylates), BYK® 347 (polyether-modified siloxane), leveling agents based on (meth)acrylic homopolymers, rheology control agents, thickeners such as partially crosslinked polycarboxylic acids or polyurethanes, and defoaming agents. Other additives may be used in conventional amounts well known to those skilled in the art. In embodiments, the wetting agents, leveling agents, flow control agents, and surfactants of the coating composition may affect the surface tension of the coating composition and, therefore, the printability of the coating composition. Certain wetting agents, leveling agents, flow control agents, and surfactants may be incorporated into the coating composition to increase or decrease the surface tension of the coating composition.

[0093] In various embodiments, the composition may contain no sag control agent, or may contain less than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1 weight percent of a sag control agent based on the total weight of the composition.

[0094] In some embodiments, sag control agents are used in the coating composition. Examples of such sag control agents can be found in US20220332134A1, US20220356359A1, and WO2023034764A1, the contents of which are incorporated herein by reference.

[0095] Particle size of coating composition

[0096] In various embodiments, the coating composition does not contain any component having an average particle size greater than approximately 10% of the nozzle diameter of the nozzles it has with the applicator. For example, high-efficiency "stream-on-demand" or "drop-on-demand" applicators generally include an array of small-diameter nozzles, each having a nozzle diameter of approximately 20 to 200 microns. For reliable fluid ejection, it is generally expected that the particle size of any component of the coating composition must be 10% or less of the nozzle diameter.

[0097] In various embodiments, the composition is clay- and silica-free. The term "clay-free" can mean that the composition contains less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1% by weight of clay and / or silica, based on the total weight of the composition. Alternatively, the composition may be completely clay- or silica-free. The clay is not particularly limited and may be clay particles surface-functionalized with a quaternary amine. Similarly, the silica is not particularly limited and may be organic hydrophilic phyllosilicate, amorphous silica such as CAS:92797-60-9, AEROSIL R-805 VV90, and combinations thereof. In various non-limiting embodiments, all values ​​and ranges of values, both integers and decimals, including the aforementioned values ​​and those in between, are expressly construed herein for use.

[0098] In some embodiments, the coating composition has a specific solid content, as indicated by the relative component amounts provided above. In these and other embodiments described herein, it will be understood that a higher solid content may be typically desired for the coating composition due to the fact that the coating composition is not atomized as in other methods utilizing conventional spray devices. In this embodiment, a lower initial solid content may be utilized in the method for the "assistance" provided by the emitter used in the method (e.g., to improve fluidity, leveling, jettisonability, etc.). Typically, the specific solid content or coating composition is selected considering the other components present in the coating composition and used in the method.

[0099] In some embodiments, the coating composition is a solvent-based composition having an initial solids content of about 25% to about 60%, for example, about 27% to about 55%, or about 30% to about 50%. In other embodiments, the coating composition is a water-based composition having an initial solids content of about 5% to about 45%, for example, about 8% to about 35%.

[0100] In some embodiments, the coating composition has a specific viscosity, such as a particular shear viscosity or complex viscosity, or other rheological properties. Those skilled in the art will understand the factors that affect the viscosity of the composition (including those involved in the method), as well as the methods for determining specific viscosities and associated values ​​(e.g., ASTM 2196). Illustrative ranges and values ​​for these properties are further described below.

[0101] In view of the various properties of coating compositions and high-efficiency applicators used with them, and particularly with respect to application using high-efficiency applicators, one or more relationships can be established between such properties to form a coating composition having properties suitable for application. For example, to describe one or more of these properties of a coating composition and a high-efficiency applicator, for example, to determine the boundaries of properties that make the coating composition suitable for application and / or use, various equations can be applied, derived therefrom, and / or used. In certain embodiments, the boundaries of properties of a coating composition can be determined by establishing the Ohnesolzi number (Oh), the Reynolds number (Re), the Deborah number (De), or a combination thereof of the coating composition.

[0102] The Ohnesorge number (Oh) is generally a dimensionless constant relating to the tendency of a coating composition droplet to remain a single droplet or separate into multiple droplets (i.e., satellite droplets) upon contact with a substrate, taking into account the viscosity and surface tension of the coating composition. The Ohnesorge number (Oh) can be determined according to the following equation I: JPEG2026519741000002.jpg14150 Here, η represents the viscosity of the coating composition in Pascal-seconds (Pa*s), and ρ is in kilograms per cubic meter (kg / m³). 3 σ represents the density of the coating composition, σ represents the surface tension of the coating composition in Newtons / meter (N / m), and D represents the nozzle diameter of the high transfer efficiency applicator in meters (m). The Ohnesorge number (Oh) can be in the range of about 0.01 to about 50, or about 0.05 to about 10, or alternatively about 0.1 to about 2.70. The Ohnesorge number (Oh) can be at least 0.01, or at least 0.05, or at least 0.1. The Ohnesorge number (Oh) can be 50 or less, or 10 or less, or 2.70 or less.

[0103] The Reynolds number (Re) is a dimensionless constant generally related to the flow pattern of a coating composition, and in certain embodiments, it relates to the flow pattern that extends between laminar and turbulent flow by considering the viscous and inertial forces of the coating composition. The Reynolds number (Re) can be determined according to the following equation II: JPEG2026519741000003.jpg6170 Here, ρ is the density of the coating composition in kg / m³ 3 The values ​​are expressed as follows: v is the collision velocity of the high-efficiency applicator in meters / second (m / s), D is the nozzle diameter of the high-efficiency applicator 12 in m, and η is the viscosity of the coating composition in Pa*s. The Reynolds number (Re) can be in the range of about 0.01 to about 1,000, or about 0.05 to about 500, or about 0.34 to about 258.83. The Reynolds number (Re) can be at least 0.01, or at least 0.05, or at least 0.34. The Reynolds number (Re) is 1,000 or less, or 500 or less, or 258.83 or less.

[0104] The Deborah number (De) is a dimensionless constant that generally relates to the elasticity of a coating composition and, in certain embodiments, relates to the structure of a viscoelastic material by considering the relaxation time of the coating composition. The Deborah number (De) can be determined according to the following equation III: JPEG2026519741000004.jpg6170 Here, λ represents the relaxation time of the coating composition in seconds (s), and ρ represents the density of the coating composition in kg / m³. 3 The formula is expressed as follows: D represents the nozzle diameter of the high transfer efficiency applicator 12 in m, and σ represents the surface tension of the coating composition in N / m. The Deborah number (De) can be in the range of approximately 0.01 to approximately 2,000, or approximately 0.1 to approximately 1,000, or alternatively, approximately 0.93 to approximately 778.77. The Deborah number (De) can be at least 0.01, or at least 0.1, or at least 0.93. The Deborah number (De) can be 2,000 or less, or 1,000 or less, or 778.77 or less.

[0105] In various embodiments, the Deborah number (De) can be in the range of greater than approximately 0 to approximately 0.01, greater than approximately 0 to approximately 0.009, greater than approximately 0 to approximately 0.008, greater than approximately 0 to approximately 0.007, greater than approximately 0 to approximately 0.006, greater than approximately 0 to approximately 0.005, approximately 0.004 to approximately 0.004, approximately 0.003 to approximately 0.003, approximately 0.002 to approximately 0.002, approximately 0.001 to approximately 0.001, from approximately 0.001 to approximately 0.009, from approximately 0.002 to approximately 0.008, from approximately 0.003 to approximately 0.007, from approximately 0.004 to approximately 0.006, or from approximately 0.004 to approximately 0.005. In various non-limiting embodiments, all of the above values ​​and ranges of values, including both integers and fractions between them, are expressly construed herein for use.

[0106] The Weber number (We) is generally a dimensionless constant related to fluid flow where an interface exists between two different things. The Weber number (We) can be determined according to the following equation IV: TIFF2026519741000005.tif6150 Here, D represents the nozzle diameter of the high-efficiency applicator 12 in m, v represents the impact velocity of the high-efficiency applicator in meters / second (m / s), and ρ represents the density of the coating composition in kg / m³ 3 This is expressed as σ, where σ represents the surface tension of the coating composition in N / m.

[0107] The Weber number (We) may be in the range of greater than 0 to about 16,600, or about 0.2 to about 1,600, or about 0.2 to about 10. The Weber number (We) may be at least 0.01, or at least 0.1, or at least 0.2. The Weber number (We) may be 16,600 or less, 1,600 or less, or 10 or less.

[0108] In typical embodiments, the coating composition may have an Ohnesorge number (Oh) of about 0.01 to about 12.6, or about 0.05 to about 1.8, or about 0.38. In these or other embodiments, the coating composition may have a Reynolds number (Re) of about 0.02 to about 6,200, or about 0.3 to about 660, or about 5.21. In these or other embodiments, the coating composition may have a Deborah number (De) greater than 0 to about 1730, or greater than 0 to about 46, or about 1.02. In these or other embodiments, the coating composition may have a Weber number (We) greater than 0 to about 16600, or greater than about 0.2 to about 1600, or about 3.86.

[0109] From the viewpoint of one or more of the above formulas, the coating composition has a concentration of about 700 to about 1500, or about 800 to about 1400, or about 1030 to about 1200 kilograms per cubic meter (kg / m³). 3 The density (ρ) of the amount can be expressed. The coating composition has a density of at least 700, or at least 800, or at least 1030 kg / m³. 3 The density (ρ) of the amount can be expressed. The coating composition is 1500 or less, or 1400 or less, or 1200 kg / m³. 3 The following densities (ρ) can be shown. The density (ρ) can be determined according to ASTM D1475.

[0110] The coating composition may exhibit a surface tension (σ) of about 0.001 to about 1, or about 0.01 to about 0.1, or about 0.024 to about 0.05 Newtons / meter (N / m). The coating composition may exhibit a surface tension (σ) of at least 0.001, or at least 0.01, or at least 0.015 N / m. The coating composition may exhibit a surface tension (σ) of 1 or less, or 0.1 or less, or 0.05 or less N / m. The surface tension (σ) can be determined according to ASTM D1331-14.

[0111] The coating composition may exhibit a relaxation time (λ) of approximately 0.00001 to approximately 1, or approximately 0.0001 to approximately 0.1, or approximately 0.0005 to approximately 0.01 seconds (s). The coating composition may exhibit a relaxation time (λ) of at least 0.00001, or at least 0.0001, or at least 0.01 seconds. The coating composition may exhibit a relaxation time (λ) of 1 or less, or 0.1 or less, or 0.01 or less. The relaxation time (λ) can be determined by a stress relaxation test performed on a strain-controlled rheometer. In such a test, a sample of viscoelastic fluid (e.g., the coating composition) is held between parallel plates, and an instantaneous strain is applied to one side of the sample. The other side is kept constant, and the stress (proportional to torque) is monitored. The resulting stress decay is measured as a function of time, and the stress relaxation modulus (i.e., stress divided by the applied strain) is obtained. In many fluids, the stress relaxation modulus decays exponentially with respect to the relaxation time as the damping constant.

[0112] The coating composition can be used to coat any type of substrate known in the art, insofar as the conditions of the method can be achieved (i.e., the coating composition can be irradiated with an emitter, etc.). As such, and as further described below, the term “substrate” is used to refer generally to the article to be coated, and will be understood not strictly to be the surface on which the coating is applied (i.e., the surface supports the irradiated coating composition, the layer formed therefrom, etc., as described herein). In embodiments, the substrate is a vehicle, automobile, or motor vehicle. “Vehicle” or “automobile” or “motor vehicle” means automobiles, e.g., automobiles, vans, minivans, buses, SUVs (sports utility vehicles); trucks; semi-trucks; tractors; motorcycles; trailers; ATVs (all-terrain vehicles); pickup trucks; heavy mobile machines such as bulldozers, mobile cranes, and earth movers; airplanes; boats; ships; and other means of transport. The coating composition can also be used to coat substrates in industrial applications such as buildings, fences, ceramic tiles, fixed structures, bridges, pipes, and cellulosic materials (e.g., wood, paper, and textiles). The coating composition can also be used to coat substrates in consumer product applications such as helmets, baseball bats, bicycles, and toys. It should be understood that the term “substrate” as used herein may also refer to a coating layer placed on an article that can also be considered a substrate. In this embodiment, the method may comprise a wet-on-wet application or a wet-on-dry application.

[0113] For example, in some embodiments, the substrate is a coated article, such as a vehicle part coated with a base coat, on which the coating composition is applied. In such cases, the substrate may be further defined as a coated substrate. In such embodiments, the method may include one or more conditioning steps to prepare the substrate for application of the coating composition. For example, in certain embodiments, the substrate is dehydrated before application of the coating composition (i.e., the substrate is further defined as a dehydrated substrate so that the method utilizes a dehydrated substrate). In such embodiments, the application of the coating composition is performed as a wet-on-dry application. In certain embodiments, the choice of coating composition has an effect.

[0114] Various substrates can include two or more discrete parts of different materials. For example, a vehicle can include a body part containing metal and a trim part containing plastic. Due to the limitations of the baking temperature of plastic (80°C) compared to metal (140°C), the body part containing metal and the trim part containing plastic may conventionally be coated in separate facilities, which increases the likelihood of inconsistencies in the coated parts. A coating composition suitable for plastic substrates can be applied to a plastic substrate using a high-transfer-efficiency applicator without the need to mask the substrate after application and baking, and without wasting any of the coating composition due to conventional low-transfer-efficiency application methods such as spray atomization. A coating composition suitable for plastic substrates can be applied using a first high-transfer-efficiency applicator, and a coating composition suitable for metal substrates can be applied using a second high-transfer-efficiency applicator. The first and second high-transfer-efficiency applicators may form a high-transfer-efficiency applicator assembly.

[0115] The high-transfer-efficiency applicator may be used in line with other conventional coating techniques. For example, in a particular embodiment, one or more coatings are applied to a substrate via a conventional coating method (e.g., spraying), and then the coating composition is applied via the high-transfer-efficiency applicator. In this embodiment, the coating prepared using the coating composition can be defined as an overspray-free coating compared to the conventional application methods used for the other one or more coatings applied to the substrate.

[0116] This method includes the step of applying a coating composition to a substrate via a high-transfer-efficiency applicator, for example, via a nozzle, in order to form a coating layer on the substrate. The application step is not particularly limited. In various embodiments, the application step may be further defined as ejection, for example, ejection via a high-transfer-efficiency applicator. Alternatively, the application step may be further defined as printing. In certain embodiments, the application step may be defined as digital printing.

[0117] In a typical embodiment, a coating composition is ejected from one or more nozzles of a high-transfer-efficiency applicator in a manner designed / controlled to form a fine stream that may or may not decompose into droplets. This stream is targeted onto a substrate so that droplets reach specific locations to potentially form a continuous film or pattern on the object. As a result, in some embodiments, there is essentially no overspray (droplets missing their target) and nearly 100% transfer efficiency (all paint reaching its target on the substrate). This type of device can be described as drop-on-demand, stream-on-demand, overspray-free, or ultra-high-transfer-efficiency applicator. These devices differ from spray atomizing devices and techniques in which energy such as pneumatic, hydraulic, or centrifugal force is introduced to create a partially controlled, random distribution of droplet size, trajectory, and velocity, and then some additional mechanism, such as electrostatics and / or shaping air, guides the paint droplets onto the substrate. Compared to conventional paint sprays, there is always some overspray and reduced transfer efficiency.

[0118] As introduced above, the application step can be further defined as spraying or printing through or by a high-transfer-efficiency applicator. In certain embodiments, the application step generates droplets or streams of the coating composition that collide with the substrate. In various embodiments, at least about 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, or higher % of the coating composition discharged from the high-transfer-efficiency applicator comes into contact with the substrate. Without being bound by theory, an increase in the number of droplets that come into contact with the substrate relative to the number of droplets that do not come into contact with the substrate by entering the environment is considered to improve the application efficiency of the coating composition, reduce waste generation, and reduce maintenance.

[0119] In various embodiments, at least about 99.5, 99.6, 99.7, 99.8, 99.9, or higher percentages of droplets of the coating composition discharged from a high-transfer-efficiency applicator are monodisperse such that the droplets have a particle size distribution of less than about 20%, or less than about 15%, or less than about 10%, or less than about 5%, or less than about 3%, or less than about 2%, or less than about 1%, or less than about 0.1%. While conventional applicators rely on atomization to form a “mist” of atomized droplets of the coating composition having a dispersed particle size distribution, the monodisperse droplets and / or flow formed by a high-transfer-efficiency applicator can be directed towards a substrate, thereby resulting in improved transfer efficiency compared to conventional applicators.

[0120] During the application step of the coating composition, the loss of volatile substances after application through a high-transfer-efficiency applicator is typically less than about 1 or about 0.5 weight percent of active substances based on the total weight of the coating composition, attributable to the applicator itself. For example, without counting any effects of the emitter and / or irradiation, this amount may be less than about 0.4, 0.3, 0.2, or 0.1 weight percent of active substances based on the total weight of the coating composition. Typically, the term “volatile substances” is defined as substances that evaporate under printing conditions, thereby resulting in a weight loss of the coating composition itself. The loss of volatile substances after application is determined by the increase in solids percentage after application compared to before application. Such increases in solids, particularly solids during work application, are described in further detail herein.

[0121] Due to insufficient atomization during the application of the coating composition, drying components can be used with the applicator, for example, as part of a single system or as independent components. Examples of suitable drying components include heaters, forced air dryers, UV lamps, and others are well known and readily conceivable by those skilled in the art. However, it will be understood that such drying components in this embodiment are separate from (i.e., used in addition to) the emitter, which may include similar components used to selectively irradiate the composition for viscosity building, as described herein.

[0122] This method includes the step of irradiating the coating composition via an infrared emitter. The irradiation is not particularly limited and can generally be selectively performed during and / or after the application of the coating composition to the substrate, as detailed herein.

[0123] As those skilled in the art will understand, irradiation parameters such as irradiation frequency, intensity, and irradiation time can be varied. Accordingly, the specific parameters used are selected in consideration of the specific components, steps, and desired results in the method being implemented, as revealed by the results of the exemplary embodiments described herein.

[0124] The duration of irradiation is not particularly limited within the practical scope of the described process. More specifically, portions of the coating composition may be exposed to radiation for a moment (e.g., on a femtosecond scale), or for seconds, minutes, or even hours, depending on the component setup employed. Specific durations are limited by the type of emitter and / or setup used and can be preset or adjusted in real time (e.g., manually, in response to autonomous monitoring, or both).

[0125] In some embodiments, for example, the emitter is provided from a carbon infrared emitter, and the irradiation duration (i.e., the duration for which a given portion of the coating composition is irradiated) is about 1 second to about 1 hour, for example, 5 seconds to about 30 minutes, or about 10 seconds to about 25 minutes, or about 15 seconds to about 25 minutes, or about 30 seconds to about 20 minutes, or about 45 seconds to about 20 minutes, or about 1 to about 20 minutes. In some such embodiments, the coating composition is irradiated multiple times (e.g., 2, 3, 4, 5, or more than 2 times), in which case the above values ​​may represent a single irradiation duration, and the total duration in some embodiments is a multiple thereof, depending on the specific number of irradiation cycles employed.

[0126] It should be understood that the above durations can also be used for various other emitters, including those using LED (or OLED) lamps, quartz envelope halogen (or other types of incandescent) lamps, etc.

[0127] Irradiation may be continuous or discontinuous with respect to the coating composition applied to the substrate. That is, the emitter can operate in cooperation with the applicator's print head, but does not need to be synchronized. In this way, the emitter can be selectively activated / deactivated, for example, used on vertical print areas and not on horizontal print areas. Furthermore, the emitter can be operated to irradiate the lower edge of the vertical surface rather than the upper or middle edge. Thus, it will be understood that this method provides an efficient single-composition coating solution for highly contoured parts, including selective irradiation of the coating composition to minimize sagging while enabling appropriate flow and leveling to obtain good or excellent appearance characteristics.

[0128] As described above, specific additives (e.g., co-solvents) can be incorporated into the coating composition to facilitate selective adjustment of the rheological profile of the composition during and after application to the substrate. Such additives can be specifically selected (e.g., based on solvent compatibility, boiling point, IR absorption, etc.) taking into consideration the emitter used with the applicator, as well as the composition itself (e.g., in terms of rheological, application, and performance characteristics). For example, a viscosity-reducing co-solvent can be added to the coating composition to achieve a desired rheological profile, thereby enabling improved flow and leveling during application. In such cases, the co-solvent can be rapidly removed during irradiation, thus enabling rapid viscosity construction of the composition through an increase in solid content during application, while also achieving selective control to prevent sagging, excessive flow, etc.

[0129] As described above, selective irradiation can be localized to specific parts of the coating being formed, such as the edges of the printed area or parts of the substrate with vertical or inclined contours. Accordingly, in some embodiments, the method comprises selectively adjusting the viscosity and / or solid content of the coating composition during and / or after application to the substrate. Due to the nature of the high transfer efficiency applicator process used, such tailoring typically involves a localized (or overall, if performed concurrently with or inline with application) increase in solid content, as well as corresponding rheological changes such as an increase in viscosity. For example, selectively controlling the duration and / or peak wavelength of infrared radiation can raise the local temperature of the coating composition above the boiling point of the solvent present in the coating composition, thereby increasing the viscosity built up from the evaporation of the solvent by the infrared radiation. In specific cases, controlling infrared radiation involves tailoring the radiation to the solvent, for example, by selecting a wavelength band (i.e., broadband or narrowband) that affects the solvent or carrier while minimizing the impact on other components involved, by using pulsed and / or continuous irradiation, by selecting a specific irradiation time, or a combination thereof. Furthermore, since a rise in temperature typically corresponds to a corresponding decrease in viscosity in the film-forming components of the composition, irradiation can influence a rapid increase in solids content, thereby being used to reduce the net viscosity loss that would result from the rise in temperature during the drying of the coating being prepared, for example. In specific embodiments, continuous infrared irradiation can be combined with pulsed irradiation, for example, pulsed irradiation is used to increase the solids content in areas prone to dripping or flowing.

[0130] It should be understood that irradiation of the coating composition is performed for rheological purposes, i.e., to affect the viscosity of the coating composition and to achieve improved coating performance and / or appearance characteristics. Therefore, in typical embodiments, the coating composition is not cured, reacted, dried, or otherwise substantially modified by infrared irradiation. Infrared-mediated curing components can be used in conjunction with this embodiment, but it should be understood that these are separate (e.g., additional) from this embodiment. Thus, in typical embodiments, the coating composition substantially does not contain infrared radiation-curable components, infrared radiation-activatable components, etc. In these embodiments or other embodiments, irradiation of the coating composition does not substantially dry or cure the composition.

[0131] Apart from potential solvent loss due to infrared radiation and / or corresponding heat, it will be understood from the above that coating compositions typically do not change chemically during irradiation. However, since a portion of the coating composition exposed to infrared light is distinguishable from the unirradiated portion, irradiation can be understood as preparing an irradiated coating composition. Thus, an irradiated coating composition is simply any coating composition that has been irradiated. In this way, it is possible and often desired, for example, to selectively control the application results and affect the appearance of the coating layer prepared therein by irradiating or not irradiating different portions of the as-applied coating composition.

[0132] Generally, an irradiated coating composition differs from the original coating composition in terms of solid content and / or viscosity. Therefore, this method may include selectively increasing the solid content of the irradiated coating composition and / or selectively increasing the viscosity of the irradiated coating composition compared to the coating composition before exposure to infrared irradiation.

[0133] For example, the coating composition provided to the applicator typically has a solids content of about 5 to about 90, or about 5 to about 80, or about 5 to about 70, in wt.%. The solids content can be determined according to ASTM D2369-10. In certain embodiments, the coating composition is further defined as an aqueous coating composition and provided to the applicator, having a solids content of about 8 to about 35, or about 10 to about 30, in wt.%. In other embodiments, the coating composition is further defined as a solvent-mediated coating composition and provided to the applicator, having a solids content of about 30 to about 60, or about 35 to about 50, in wt.%.

[0134] Generally, irradiated coating compositions exhibit a solid content greater than the initial solid content. For example, an irradiated coating may have a solid content at least 2%, or at least 3%, or at least 5%, or at least 7%, or at least 10% greater than the initial solid content. In these embodiments or other embodiments, irradiating the coating composition involves increasing the work-grade solid content by at least 2%, or at least 3%, for example, at least 5-7%, compared to the starting solid content before irradiation, either before or after application.

[0135] For example, as described above, in some embodiments, the coating composition is a solvent-mediated composition within a specific sub-range of the above, such as an initial solids content of about 25% to about 60%, for example, about 27% to about 55%, or about 30% to about 50%. In such embodiments, the irradiated coating composition typically has a solids content at least 5%, or at least 7%, greater than the initial solids content of the coating composition.

[0136] In other embodiments, the coating composition is an aqueous composition having an initial solids content of about 5% to about 45%, for example, about 8% to about 35%, or about 10% to about 30 wt.%. In such embodiments, the irradiated coating composition typically has a solids content at least 1%, or at least 2%, or at least 3%, or at least 5%, greater than the initial solids content of the coating composition. In some embodiments, the aqueous coating composition is applied to a dehydrated substrate as described above, in which case the total difference in solids content from the as-applied coating composition to the irradiated coating composition can be distributed between the solvent transfer (i.e., interaction vias with the dehydrated substrate) and the irradiation step such that the total increase in solids content due to application is greater than the solids construction due to irradiation alone.

[0137] The coating composition provided to the applicator typically has an initial shear viscosity of about 10 to about 100 cP at a shear rate of 1000 / s. For example, in some embodiments, the coating composition exhibits an initial shear viscosity of less than about 60 cP or less than about 25 cP at a shear rate of 1000 / s. In specific embodiments, the coating composition is solvent-based and has an initial shear viscosity of about 15 to about 60, or about 15 to about 35 cP. In other embodiments, the coating composition is aqueous and has an initial shear viscosity of about 10 to about 90 cP. In such embodiments, the aqueous coating composition may be a relatively low viscosity composition having an initial shear viscosity of about 10 to about 40 cP, or a relatively high viscosity composition having an initial shear viscosity of about 40 to about 90 cP.

[0138] The specific selection of the coating composition is made considering the entire method, for example, when the use of a lower viscosity coating composition can be facilitated by the selection of a modified substrate. Specifically, the method provides the use of a relatively low viscosity coating composition when applied to a dehydrated substrate, for example, in a wet-on-dry application process. However, the method can also involve wet-on-wet application, in which case the features of this embodiment can also be benefited. For example, the substrate may have an aqueous base coat, on which the coating composition can be applied via a method for preparing an aqueous topcoat, clear coat, etc., or monocoat. In this embodiment, overspray-free / digital application of such a coating layer is provided, along with application controlled via selective adjustment and application parameters. Thus, it will be understood that the type of coating applied, the properties of the substrate to be coated, and the desired end use of the coating to be prepared each influence the specific selection of method parameters. Specific selections are illustrated in the following examples, which can be used by those skilled in the art to inform of the selection of other combinations of solvents, coating compositions, etc., in the embodiments herein.

[0139] In a typical embodiment, irradiating a coating composition involves locally increasing its viscosity, at least with respect to the irradiated coating composition thus prepared, by at least about 1%, or at least about 5%, for example, at least about 10%, 15%, 20%, 25%, or more, compared to the initial shear viscosity before application, or after application and before irradiation. For example, in some embodiments, the irradiated coating composition exhibits a shear viscosity of at least about 200 cP at a shear rate of 0.1 / s.

[0140] In various embodiments, the method further includes the step of curing a coating composition on a substrate to prepare a coated article. Curing conditions can vary and will be selected by those skilled in the art based on the specific coating composition used.

[0141] Several exemplary embodiments are provided with reference to the drawings. In particular, a high transfer efficiency applicator system comprising an applicator and emitter is shown in Figures 1-4.

[0142] Looking at Figures 1A-1C, the high-transfer-efficiency applicator 12 ejects the coating composition 14 onto the substrate 16. More specifically, the applicator 12 makes adjacent passes to lay stripes 20 of the coating composition 14. In Figure 1A, each stripe 20 represents a single pass of approximately 50 nozzles on the print head of the applicator 12.

[0143] Figure 1A shows a space 18 between the new stripe to be printed and a stripe 20 already applied on the substrate 16. This space 18 is preferably minimized or removed. However, those skilled in the art will understand that overlapping stripes 20 with conventional coating compositions can unintentionally lead to overlap defects through the formation of undesirable accumulation of the composition and a kind of "hill" or raised section of the substrate, as well as "valleys" or low sections of the substrate. In this embodiment, this is also preferably minimized as the rheological profile of the coating composition allows for the reduction of overlap defects. More specifically, the adoption of an emitter 30, shown in Figures 1A-1C, coupled to the applicator 12, allows the coating composition to be used in a more fluid state via vias that allow the flow and leveling composition, once applied (e.g., as stripe 20) before irradiation, to build viscosity and prevent sagging if necessary. In this embodiment, the emitter 30 is used to assist the applicator 12 by controlling the viscosity of the composition 14. This configuration allows for selective solvent evaporation, suppressing dripping, ensuring sufficient solvent is present to achieve good flow and leveling, and also providing good to high gloss and DOI.

[0144] With respect to Figure 1B, an embodiment is shown in which the emitter 30 is powered by the supply unit 32 and irradiates the coating composition 14 during application. More specifically, the emitter 30 supplies IR radiation 34 to a portion of the coating composition 14 that constitutes the stripe 20, i.e., the portion already present on the substrate 16. In another embodiment shown in Figure 1C, the emitter 30 is configured to irradiate the composition 14 before and / or during application to the substrate 16.

[0145] In the embodiments shown in Figures 1A to 1C, the print heads of the emitter 30 and the applicator 12 are both fixed. Thus, the substrate 16 can move relative to the fixed position of the applicator 12, or the applicator 12 can move relative to the fixed position of the substrate 16, or both.

[0146] Another configuration is provided in Figure 2, where the emitter 30 is not mounted on the applicator 12. In this configuration, the emitter 30 can be used to provide continuous IR emission 34 over a wide area of ​​the substrate 16. The emitter 30 can move independently of the substrate 16, or it can be fixed in a position relative to the substrate 16. Similarly, the substrate 16 and the emitter 30 may be movable relative to the fixed position printhead of the applicator 12.

[0147] Figure 2 also illustrates a single nozzle line being applied from the applicator 12.

[0148] Typically, nozzle lines give the applied coating a streaky appearance, with visible lines spaced at the same distance as the nozzles of the applicator 12. Thus, application lines may be visible immediately after application, but preferably become less visible over time as flow and leveling occur. However, if sufficient flow and leveling do not occur, the lines may still be visible after the coating has cured, thereby giving the coating an uneven and generally undesirable appearance. In specific embodiments, a coating layer without overspray is substantially free of visible application lines.

[0149] Overlapping stripe defects may also exist parallel to the application direction (e.g., X). Although they may exist parallel to X), these defects are not related to the applicator nozzle spacing and only exist when the application of adjacent stripes 20, applied sequentially next to each other, overlaps and is visible on a length scale of 5-10 mm, i.e., perpendicular to the application direction. In some embodiments, coating layers without overspray are substantially free of visible overlapping stripe defects.

[0150] Figures 3A-3B provide another example in which the emitter 30 is detached from the applicator 12 and the emitter 30 irradiates a portion of the stripe 20 that has been applied. In such an embodiment, the irradiation by the emitter 30 is detached from the applicator 12 but is configured to irradiate the stripe 20 for a post-application time represented by time points T1-T3 along the application direction. This method is typically performed as part of a coating step, for example, to prepare a coated article having an overspray-free coating layer on a substrate.

[0151] In various embodiments, the coating composition may be further defined as, in particular, an automotive OEM coating composition, an automotive refinishing coating composition, an industrial coating composition, a building coating composition, a coil coating composition, or an aerospace coating composition.

[0152] In some embodiments, the method is carried out in line with other coating processes, such as those used for preparing substrates for coating (e.g., conditioning, stripping, priming, etc.) and / or finishing coated substrates (e.g., top coating, clear coating, surface finishing, etc.). In some embodiments, the coating composition is a base coat, and the method further includes steps before and / or after applying the base coat, such as a primer or clear coat. In other embodiments, the composition is a monocoat, and the method further includes steps before and / or after applying the monocoat, such as a primer. Examples of other embodiments are as follows:

[0153] The following embodiments are illustrative of the embodiments of the present disclosure and do not limit the present invention.

[0154] All parts and percentages are reported on a weight basis unless otherwise specified. Where provided, molecular weights (both number-average and weight-average molecular weights) referred to herein can be determined by conventional methods known in the art. For example, the molecular weight of polyaspartic acid resins can be determined, for instance, by gel permeation chromatography (GPC) using a polystyrene standard and tetrahydrofuran (THF) eluent. Unless otherwise noted, molecular weights are reported as weight-average molecular weights (Mw).

[0155] (material) Unless otherwise noted, all solvents, substrates, and reagents were purchased or otherwise obtained from various commercial suppliers (e.g., BASF, Covestro, Evonik, Sigma-Aldrich, VWR, Alfa Aesar, etc.) and used as received (i.e., without further purification) or in forms conventionally used in the art.

[0156] Various coating compositions were prepared using the following specific materials: JPEG2026519741000006.jpg181164 JPEG2026519741000007.jpg202164 JPEG2026519741000008.jpg192164

[0157] A solvent-based coating composition (SB1) was formulated and prepared using the above components. The specific components and parameters are shown in the table below. JPEG2026519741000009.jpg144153

[0158] Furthermore, three additional solvent-based coating compositions (SB2, SB3, and SB4) were prepared using the above components. These compositions were formulated for overspray-free application according to the methods described herein and used in the print tests shown below. The specific components and parameters of the solvent-based compositions are shown in the table below. JPEG2026519741000010.jpg58153

[0159] The formulated and prepared SB2 represents a one-component solvent-based monocoat composition with a viscosity of 29.6 cP at 25°C. SB3 represents a one-component solvent-based basecoat composition with a viscosity of 42.5 cP at 25°C. SB4 represents a one-component solvent-based monocoat composition with a viscosity of 64.9 cP at 25°C.

[0160] Figure 4 shows the comparative viscosity profiles of coating compositions SB2, SB3, and SB4.

[0161] Aqueous coating compositions (WB) were formulated and prepared using the components further specified above to obtain WB1 to WB7. The specific components and parameters are shown in the table below. JPEG2026519741000011.jpg169160 JPEG2026519741000012.jpg201160 Print Trial 1: SB2 Critical Film Thickness

[0162] SB2 was printed on a flat horizontal plate at a density of 1440 DPI using a high transfer efficiency applicator to obtain a first sample coating, and then printed at 720 DPI to obtain a second sample coating. The sample coatings were visually evaluated to determine the estimated critical film thickness, i.e., the print density suitable for obtaining a coating appearance as uniform as possible.

[0163] As shown in Figure 5A, the coating on the 1440 DPI sample has a uniform appearance, while the 720 DPI sample (Figure 5B) has a dark ring around the coated area and appears lighter in the center. Therefore, 1440 DPI exceeds the critical film thickness of SB2, while 720 DPI falls below the critical film thickness of SB2. Print Trial 2: SB4 1440 DPI

[0164] SB4 was printed using a high-transfer-efficiency applicator at a density of 1440 DPI to match the critical film thickness conditions determined for SB2 above.

[0165] SB4 was printed on a flat horizontal plate (29V, 27°C) and then stood upright for air drying before being suspended vertically in an oven (140°C) to cure. Images of the coating layer at each time point during vertical storage are shown in Figure 6.

[0166] As shown in the figure, the bottom edge of the coating area formed a bead in less than 8 seconds, complete dripping was formed in ~20 seconds, and reached the edge of the plate before drying (6 minutes). Inspection revealed that the print start area was thinned to below the critical film thickness (~10 μm), and fluid accumulated at the print end area, flowing beyond the original edge of the print area. Print Trial 3: SB4 720 DPI

[0167] To evaluate the correlation between film thickness and sagging, SB4 was printed at a lower laydown density of 720 DPI according to print test 2 described above. A second plate was also printed and heated with a heat gun for 15 minutes. Images of the coating layer at various times during vertical storage are shown in Figure 8. A third plate (not shown) was also printed and dried vertically, but then laid flat for curing.

[0168] As shown in the figure, the 720 DPI density of SB4 performed far better in terms of visual sagging than the higher laydown densities tried in print test 2. Furthermore, 720 DPI is shown to be above the critical film thickness of SB4. Additionally, the added heat gun drying step is shown to coincide with the 50-second time point after 15 minutes.

[0169] When samples dried with a heat gun were examined, it was observed that the beginning of the print was thin, but remained above the critical film thickness. Some fluid accumulated at the edges of the print, but it did not extend beyond the edges of the print area.

[0170] The flat-cured sample showed slight accumulation at the edges, and the film thickness difference from start to finish was 1 μm, but it appeared to stabilize immediately. Print Trial 4: SB3 720 DPI

[0171] SB3 was printed according to print test 2 described above. Figure 7 shows an image of the coating layer after 15 minutes. As shown, SB3 had a viscosity approximately 22 cP lower than SB4, while SB3 exhibited significantly less dripping, even at a laydown density of 1440 DPI. The coating layer was completely fixed and dried within 15 minutes, with a drip length of only about 1 / 3 of that of SB4 after 6 minutes at the same 1440 DPI (print test 2). Upon inspection, the coating from SB4 exhibited an orange peel-like surface texture. Example 1 and Comparative Examples 1 and 2

[0172] Based on the print test results, coating compositions SB5(30cP) and SB5(60cP) were selected for comparative print testing. These coating compositions are representative of single-component solvent-type monocoat compositions.

[0173] SB5 (30 cP) was used in Example 1 and Comparative Example 1. SB6 (60 cP) was used in Comparative Example 2, and the sag correlation with viscosity at the same laydown density was evaluated, confirming the effectiveness of the sag prevention performance of selective irradiation used in Example 1.

[0174] Each coating composition was printed on a flat, horizontal panel using a stationary printer equipped with an NIR lamp mounted near the print head and a movable print base (table).

[0175] The printing conditions were selected to print at 1080 DPI at 50 mm / s, resulting in a dry film thickness of 0.6 mil. In Example 1, after applying (printing) the coating composition, the panel was irradiated twice with an NIR lamp after printing. The coated panel was then dried vertically and visually evaluated.

[0176] For Comparative Examples 1 and 2, no irradiation was performed (infrared irradiation was omitted), and the printing conditions were the same as described above.

[0177] The results for Example 1 and Comparative Examples 1 and 2 are shown in Figures 9A to 9C.

[0178] As shown in the figure, selective irradiation of SB5 during application in Example 1 (Figure 9A) resulted in a significant reduction in the amount of as-printed composition on the panel compared to Comparative Example 1 (Figure 9B) without irradiation, while maintaining good appearance characteristics.

[0179] Comparative Example 2 (Figure 9C) shows that increasing viscosity reduces sagging. However, compositions with increased viscosity exhibited poor print quality with significant visual defects characteristic of poor flow and poor leveling. Additional examples

[0180] Coating compositions SB1 and WB1-7 were evaluated, and their initial viscosity and solid content were determined. Each composition was then applied using the method described above, and the solid content during application was measured after irradiation. An increase of at least 7% in solid content was observed for the solvent-based composition SB1.

[0181] Therefore, this embodiment provides a method that can achieve balanced print performance (e.g., low sag, good flow, and leveling) while maintaining good coating appearance characteristics. Furthermore, specific embodiments of this embodiment can provide performance and / or appearance superior to comparative methods.

[0182] The data presented indicates that the exemplary compositions exhibit good performance and can be used to successfully prepare coatings without overspray, and that some exemplary coatings provide superior performance and appearance compared to comparative coating compositions.

[0183] While at least one exemplary embodiment has been described in the detailed description above, it should be understood that a vast number of variations exist. It should also be understood that exemplary embodiments are merely illustrative and are not intended to limit their scope, applicability, or configuration in any way. Rather, the detailed description above provides a convenient roadmap for carrying out exemplary embodiments. It should be understood that various modifications can be made to the function and arrangement of the elements described in the exemplary embodiments above without departing from the scope defined in the appended claims. Furthermore, all combinations of the aforementioned components, compositions, method steps, formulation steps, etc., are expressly intended to be used in various non-limiting embodiments herein, even if such combinations are not expressly described in the same or similar paragraphs.

[0184] With respect to any group of Markush referenced herein to describe specific features or aspects in various embodiments, different, special, and / or unexpected results may be obtained from each member of each Markush group, independently of all other members of the Markush group. Each member of a Markush group can be relied upon individually and / or in combination to provide appropriate support in specific embodiments of the appended claims.

[0185] Furthermore, the ranges and subranges on which various embodiments of the present invention are relied upon, independently and collectively, are included in the appended claims and are understood to describe and encompass all ranges, including integers and / or decimal values, even if such values ​​are not expressly stated herein. Those skilled in the art will readily recognize that the ranges and subranges enumerated herein are sufficient to describe and enable various embodiments of the present invention, and that such ranges and subranges can be further subdivided into relevant half, one-third, one-quarter, one-fifth, etc. For example, the "range of 0.1 to 0.9" can be further subdivided into a lower third, i.e., 0.1 to 0.3, a middle third, i.e., 0.4 to 0.6, and an upper third, i.e., 0.7 to 0.9, which, individually and collectively, are within the scope of the appended claims and can be relied upon individually and / or collectively, providing sufficient support for specific embodiments within the appended claims. In addition, with regard to phrases that define or modify ranges such as "at least," "greater than or equal to," "less than," and "less than or equal to," it should be understood that such phrases include smaller ranges and / or upper or lower limits. As another example, the range "at least 10" essentially includes subranges such as at least 10 to 35, at least 10 to 25, 25 to 35, etc., and each subrange can be relied upon individually and / or collectively to provide sufficient support for a particular embodiment within the appended claims. Individual numbers within the disclosed ranges can be relied upon to provide appropriate support for a particular embodiment within the appended claims. For example, the range "from 1 to 9" includes various individual integers such as 3, as well as individual numbers including decimals (or fractions) such as 4.1, which can be relied upon to provide appropriate support for a particular embodiment within the appended claims. Finally, the term “about” relating to any particular numerical value or range described herein will be understood to be used to specify values ​​within a range such as standard error, equivalent function, efficacy, final load, etc., as understood by those skilled in the art who have the relevant prior art and processes for formulating and / or utilizing compounds and compositions as described herein.Thus, the term "approximately" can specify a value within 10, 5, 1, 0.5, or 0.1 of the listed values ​​or ranges.

[0186] While this disclosure is described in its specific embodiments, it is evident that numerous other forms and modifications will be apparent to those skilled in the art. The appended claims and this disclosure should generally be construed to cover all such obvious forms and modifications that fall within the true scope of this disclosure. [Explanation of symbols]

[0187] 12 High Transfer Efficiency Applicators 14 Coating composition 16 circuit boards 20 Stripes 30 Emitter 32 Supply section 34 IR radiation

Claims

1. A method for applying a coating composition to a substrate using a high-transfer-efficiency applicator to form a coating layer on the substrate, A high transfer efficiency applicator is provided, comprising a plurality of nozzles, each configured to apply a stream or droplet of the coating composition to a substrate substantially without atomization, and an infrared emitter. To provide a coating composition for application to the aforementioned high transfer efficiency applicator without overspray, wherein the coating composition exhibits an initial shear viscosity of about 10 to 100 cP and / or an initial solids content of about 5 to about 70% at a shear rate of 1000 / second, and comprises a carrier, a binder present in an amount of 5 to about 70 wt.% based on the total weight of the coating composition, and a crosslinking agent present in an amount of about 0.1 to about 25 wt.% based on the total weight of the coating composition. The coating composition is applied to the substrate by the high-transfer-efficiency applicator by arranging multiple lines of the coating composition on the substrate via the multiple nozzles. The coating composition is irradiated through the infrared emitter during and / or after application to provide an irradiated coating composition exhibiting a shear viscosity greater than the initial shear viscosity and / or a solid content greater than the initial solid content. Methods that include...

2. Applying the coating composition to the substrate involves arranging partially overlapping continuous stripes of the irradiated coating composition on the substrate to provide a continuous wet film. The method further includes preparing the wet film by at least partially flushing and / or dehydrating in order to give the coating layer without overspray, (i) The wet film is substantially free of visible sagging after an optional period of at least about 30 seconds; (ii) The coating layer without overspray is substantially free from cosmetic defects resulting from incomplete flow and / or leveling from individual nozzle lines; (iii) The coating layer without overspray is substantially free of visible overlapping stripe defects; or (iv)(i) to (iii) are combinations The method according to claim 1.

3. (i) The coating composition exhibits an initial shear viscosity of less than approximately 60 cP or less than approximately 25 cP at a shear rate of 1000 / second. (ii) The irradiation coating composition exhibits a shear viscosity of more than approximately 200 cP at a shear rate of 0.1 / s, or (iii) Both (i) and (ii) The method according to claim 1.

4. (i) The coating composition is a solvent-based composition having an initial solid content of about 25% to about 60%, or about 27% to about 55%, or about 30% to about 50%, and the irradiation coating composition has a solid content that is at least 5%, or at least 7%, greater than the initial solid content of the coating composition. or (ii) The coating composition is an aqueous composition having an initial solid content of about 5% to about 45%, or about 8% to about 35%, and the irradiation coating composition has a solid content that is at least 2%, at least 3%, or at least 5% greater than the initial solid content of the coating composition. The method according to claim 1.

5. The infrared emitter is, (i) Selectively irradiate the coating composition during application so that the irradiated coating composition is formed before it is placed on the substrate. (ii) After application, the coating composition is selectively irradiated so that the irradiated coating composition is formed after the coating composition is placed on the substrate, or (iii) Perform both (i) and (ii), The method according to claim 1, configured as described above.

6. Each of the aforementioned plurality of nozzles, (i) Define a nozzle orifice having a diameter of approximately 0.00002 m to approximately 0.0004 m. (ii) Independently coupled to the print head, or (iii) Both (i) and (ii) The method according to claim 1.

7. The method according to claim 6, wherein the infrared emitter is coupled to the print head and configured to be used in close proximity to the print head.

8. The method according to claim 6, wherein the infrared emitter is not coupled to the print head and is configured to be used separately from the print head.

9. The method according to claim 8, further comprising independently controlling the position of the print head and / or the infrared emitter relative to the substrate during the application of the coating composition and / or irradiation of the coating composition.

10. The method according to claim 1, wherein the coating composition is applied using the high-transfer-efficiency applicator such that the loss of volatile substances from application through the high-transfer-efficiency applicator is less than about 1 wt.% or less than about 0.5 wt.% based on the total weight of the coating composition, at least before irradiation.

11. The coating composition is (i) Infrared radiation-hardening components; (ii) Infrared radiation activating component; or (iii)(i) and (ii) The method according to claim 1, wherein the property is substantially absent.

12. The method according to claim 1, wherein irradiating the coating composition comprises selectively controlling the duration and / or peak wavelength of the infrared radiation based on one or more solvents or carriers present in the coating composition.

13. The method according to claim 12, wherein the duration and / or peak wavelength of the infrared radiation are selectively controlled to raise the local temperature of the coating composition above the boiling point of at least one of the one or more solvents or carriers present in the coating composition.

14. The duration and / or peak wavelength of the infrared radiation are (i) Reduce viscosity loss due to temperature rise of the irradiation coating composition; (ii) Increase the viscosity of the irradiated coating composition by evaporation of the solvent or carrier; or (iii) Perform both (i) and (ii), The method according to claim 12, which is selectively controlled in such a manner.

15. The method according to claim 12, wherein the duration and / or peak wavelength of the infrared radiation are selectively controlled to increase the solid content of the coating composition, thereby giving the irradiated coating composition having a solid content during application that is at least about 5%, or at least about 7%, greater than the initial solid content of the coating composition.

16. The method according to any one of claims 12 to 15, wherein selectively controlling the duration and / or peak wavelength of the infrared radiation includes pulsing the emitter.

17. The method according to any one of claims 1 to 12, wherein the coating composition is further defined as a one-component solvent-based coating composition.

18. The coating composition is (i) The Ohnesorge number (Oh), which is approximately 0.01 to approximately 12.6, determined according to the following equation I: Here, η represents the viscosity of the coating composition in Pascal-seconds (Pa*s), and ρ represents the density of the coating composition in kilograms per cubic meter (kg / m³). 3 ) is expressed as such, where σ represents the surface tension of the coating composition in Newtons / meter (N / m), and D is approximately 0.00002 m to approximately 0.0004 m; (ii) The Reynolds number (Re) between approximately 0.02 and approximately 6,200, determined according to equation II below: Here, ρ is the density of the coating composition in kg / m³. 3 This is expressed as follows: v is approximately 1 to approximately 20 m / sec, D is approximately 0.00002 m to approximately 0.0004 m, and η is the viscosity of the coating composition expressed in Pa*s; (iii) The Deborah number (De) between 0 and approximately 0.01, determined according to equation III as follows: Here, λ represents the relaxation time of the coating composition in seconds (s), and ρ represents the density of the coating composition in kg / m³. 3 This is expressed as follows: D is approximately 0.00002 m to approximately 0.0004 m, and σ represents the surface tension of the coating composition in N / m; (iv) a density of from about 838 kg / m 3 to about 1557 kg / m 3 ; (v) Surface tension of approximately 0.015 N / m to approximately 0.05 N / m; (vi) Relaxation time of approximately 0.00001 to approximately 1 second; or (vii) Any combination of (i) to (vi) As shown, the solid content of the coating composition is selected such that at least the carrier, the binder, and the crosslinking agent are present independently in certain amounts. The method according to any one of claims 1 to 12.

19. A coated article prepared by the method according to any one of claims 1 to 12.

20. A coated article according to claim 19, further defined as a coated vehicle part.

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