Protective coating cured by pulsed IR radiation

Abstract

The present disclosure relates to a method of applying a protective coating to a substrate, the method comprising applying a fluid coating composition on at least a portion of a surface of the substrate by a precise application substantially without overspray, and applying pulsed infrared radiation to form a cured coating. Further disclosed is a substrate coated by said method and the use of a coating composition for forming a protective coating on at least a portion of a substrate by curing the applied composition by pulsed infrared radiation. The present disclosure is particularly useful for protecting a paint surface of a vehicle from stone hit.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method of applying a protective coating to a substrate, the method comprising applying a fluid coating composition to at least a portion of a surface of the substrate by precise application substantially free of overspray, and applying pulsed infrared radiation to form a cured coating. Further disclosed are substrates coated by the method and the use of the coating composition for forming a protective coating on at least a portion of a substrate by curing the applied composition by pulsed infrared radiation. The present disclosure is particularly useful for protecting the finish of a vehicle from stone chipping. BACKGROUND

[0002] Unfortunately, stone chips and other small damage, or abrasion damage, caused by, for example, abrasion during car washing, are often found in the cured finish of a vehicle in use. These damages not only worsen the appearance of the finish, but also allow moisture (e.g., rain and ice) to penetrate and affect the metal beneath the finish by corrosion. Depending on the design of the vehicle, certain areas can be more susceptible to such mechanical damage and scratching than others.

[0003] Colored sprayable rubber-based stone chip protective coatings and substantially colorless transparent stone chip protection films have been developed to protect the original finish from such environmental influences. However, both only provide a compromise between protecting the original finish and maintaining its appearance. For example, stone chip protection films can yellow over time and often do not match the gloss of the original finish, which becomes particularly evident if they are applied to only certain portions of the original finish. Furthermore, in conventional spray techniques, overspray (i.e., the spreading of the coating onto unintended areas) is a problem, which often makes it necessary to mask those portions of the surface that are not intended to be coated with a removable material. Further, if a dry film thickness of 75 pm or more is desired, sprayable products often have to be applied in several applications with intermediate drying steps until the desired layer thickness is reached.

[0004] It is desirable to provide a solution to these problems. In particular, it is desirable to have a method for applying a protective coating to a substrate (e.g., a vehicle having an existing multi-layer finish) that can be applied in one pass to result in a dry film thickness of 75 pm or more (e.g., 80 pm or more, 90 pm or more, or even 100 pm or more), and up to 200 pm or less (e.g., 180 pm or less, 150 pm or less, or 130 pm or less), without dripping or sagging during application, and without the need to mask those portions of the surface of the substrate where the coating should not be applied.

[0005] This object has been achieved by the subject matter defined in the appended claims and described herein. SUMMARY

[0006] The present disclosure relates to a method for applying a protective coating to a substrate, the method comprising: (i) applying a fluid coating composition on at least a portion of a surface of the substrate by precise application substantially free of overspray, wherein the coating composition comprises a film-forming resin and a crosslinker suitable for crosslinking the film-forming resin; and (ii) applying pulsed infrared radiation to the applied coating composition with a peak wavelength in the range of 3 to 10 pm at a pulse duration of less than 100 ps to form a cured coating.

[0007] The present disclosure further relates to a coated substrate obtained by the method.

[0008] The present disclosure also relates to the use of a coating composition comprising a film-forming resin and a crosslinker suitable for crosslinking the film-forming resin for forming a protective coating on at least a portion of a substrate by curing the protective coating composition applied to at least a portion of the substrate by applying pulsed infrared radiation to the coating with a peak wavelength in the range of 1 to 10 pm at a pulse duration of less than 100 ps. DETAILED DESCRIPTION

[0009] For the purposes of the following detailed description, it is to be understood that the disclosure can assume various alternative variations and step sequences, except where expressly indicated to the contrary, Moreover, other than in any operation examples, or where otherwise indicated, all numbers expressing amounts of ingredients, reaction conditions, and so forth, used in the specification and claims are to be understood as approximations. Unless indicated otherwise, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0010] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0011] Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed

[0012] In the present disclosure, the use of the singular includes the plural, and the plural covers the singular, unless specifically stated otherwise. Additionally, in the present application, the use of "or" means "and / or" unless specifically stated otherwise, even though "and / or" can be explicitly used in certain instances. Further, in the present application, the use of "a" or "an" means "at least one" unless specifically stated otherwise. For example, "a" polymer, "an" crosslinker, and the like refer to one or more of any of these items.

[0013] As used herein, the transitional term "comprising" (and other comparable terms, such as "containing" and "including") is "open-ended" and open to include unspecified materials. Although described in terms of "comprising," the terms "consisting essentially of and "consisting of are within the scope of the present disclosure.

[0014] As used herein, the term "comprising," and like terms, means "including, but not limited to." Similarly, as used herein, the terms "on," "applied on / over," "formed on / over," "deposited on / over," "covering," and "provided on / over" mean formed, covering, deposited, or provided on a surface, but not necessarily in contact with the surface. For example, a coating "formed on" a substrate does not exclude the presence of one or more other coatings of the same or different composition located between the formed coating and the substrate.

[0015] The present disclosure relates to a method for applying a protective coating to a substrate. The method comprises: (i) applying a fluid coating composition on at least a portion of a surface of the substrate by precision application that is substantially free of overspray; and (ii) applying pulsed infrared radiation having a peak wavelength in the range of 3 to 10 pm to the applied coating composition with a pulse duration of less than 100 ps to form a cured coating. The coating composition comprises a film-forming resin and a crosslinking agent suitable for crosslinking the film-forming resin.

[0016] As used herein, the term "protective coating" refers to a coating that makes the surface of an object coated with the coating more resistant to external influences as compared to the surface of the same object that is not coated with the protective coating. The surface to which the protective coating is applied can be at least a portion of a bare substrate surface, but can also be an existing single or multi-layer coating on at least a portion of the surface of the object. The external influences can include thermal influences, radiation influences, chemical influences, electrical influences, or mechanical influences, or combinations thereof. The method of the present disclosure can be particularly useful for protecting a vehicle finish or a portion thereof from abrasion, chip damage, and stone chipping.

[0017] As used herein, the term "fluid" refers to a material that deforms (flows) continuously under applied shear stress, in particular a liquid, i.e. a non-gaseous fluid, including non-Newtonian fluids. The coating composition can be liquid at room temperature (23 °C) and at atmospheric pressure (101.3 kPa).

[0018] As used herein, the term "substantially free of overspray" refers to the application of the coating composition with the aid of a device in such a way that overspray is avoided from drifting to unintended locations, including non-targeted areas on the coated substrate and non-substrate areas. Herein, at least 85 wt.%, or at least 95 wt.%, or at least 98 wt.%, or at least 99 wt.%, or 100 wt.% (wt.%) of the applied coating composition is deposited on the targeted areas on the surface of the substrate, despite the absence of direct contact between the surface of the substrate to be coated and the device used for applying the coating composition, as is the case with direct contact when applying the coating composition by brushing, rolling, etc.

[0019] Non-limiting examples of devices with which the coating composition can be applied substantially free of overspray include devices that apply the composition as a continuous jet, as a continuous stream of droplets, and / or as drop-on-demand. Specific non-limiting examples of such devices include continuous inkjet printers, gas-jet droplet generators, vibrating tip droplet generators, piezoelectrically actuated micro-pneumatic droplet generators, and electrohydrodynamic droplet generators.

[0020] Specific non-limiting examples of such devices include one or more nozzle applicators that are similar to inkjet print heads and differ from conventional paint atomizers in that they use a plurality of small-diameter (e.g. 0.1 mm) nozzles to direct a parallel stream, jet, or droplets of the coating composition onto the surface of the substrate. Herein, the individual nozzles can be selectively controlled and actuated with the aid of a control unit or device. With the aid of a multi-axis robot controlled and actuated by the control unit or device, the nozzle applicator can be flexibly positioned and moved over the surface to be coated in a predetermined path at a rather small distance, such as up to 30 or 25 millimeters. The plurality of nozzles can be arranged next to each other, e.g. in one or more rows, thereby forming a nozzle plate or print head. Such devices are described, for example, in European patent application EP 3 532 206 A1 and are commercially available under the trade name EcoPaintJet from Durr Systems AG (Bietigheim-Bissingen, Germany) or under the trade name PixelPaint from ABB Asea Brown Boveri Ltd (Zurich Switzerland).

[0021] As used herein, the term "nozzle" refers to a component of an applicator having an opening through which a coating composition flows, is expelled, or is sprayed. Unless otherwise stated, the term "nozzle" may be used interchangeably with any of the following: a valve-type injector or a piezoelectric, thermal, acoustic, or ultrasonically actuated valve-type injector or nozzle.

[0022] As used herein, the term "film-forming resin" refers to a resin that, upon removal of any diluent or carrier present in the composition or upon curing under ambient conditions (e.g., at temperatures in the range of 20°C to 25°C) or at elevated temperatures (e.g., at temperatures in the range of 40°C to 200°C), can form a self-supporting continuous film on at least a horizontal surface of a substrate. The terms "resin" and "of resin," etc., are used interchangeably with the terms "polymer" and "polymerized," etc., and include homopolymers and copolymers, as well as prepolymers and oligomers, unless otherwise stated. Further, the term "polymer" as used herein refers to its common meaning in the art, a macromolecular compound, i.e., a compound with a relatively high molecular weight (e.g., 500 Da or higher) whose structure comprises multiple repeating units (also referred to as "monomers") that are actually or conceptually derived from chemical nuclides with relatively low molecular weights. Unless otherwise stated, molecular weight is based on average weight ("M"). w The polystyrene standard was determined by gel permeation chromatography.

[0023] Environmental conditions refer to the curing of the composition without the aid of heat (e.g., not baking in an oven, not using forced air, etc.).

[0024] Film-forming resins may include at least one of acrylic resins, vinyl resins, polyester resins, polyether resins, polysiloxane resins, epoxy resins, polyurethane resins, polyamide resins, copolymers thereof, or mixtures thereof. Film-forming resins may include acrylic resins, such as acrylic polyol resins.

[0025] Suitable acrylic resins can be obtained by polymerizing one or more monomers comprising substituted or unsubstituted (meth)acrylic acid and (meth)acrylates. In this document, the terms "(meth)acrylic acid" and "(meth)acrylate," and similar terms, refer to acrylic acid or acrylates and their corresponding methacrylic acid or methacrylates, respectively. Suitable (meth)acrylates may include, but are not limited to, alkyl (meth)acrylates, cycloalkyl (meth)acrylates, alkylcycloalkyl (meth)acrylates, aralkyl (meth)acrylates, alkylaryl (meth)acrylates, aryl (meth)acrylates, and (meth)acrylates containing functional groups. As used herein, the term "functional group" refers to a group containing one or more dehydrogenated and sp... 3Groups consisting of atoms other than carbon atoms. Examples of functional groups include, but are not limited to, hydroxyl, carboxylic acid, amide, isocyanate, urethane, thiol, amino, sulfone, sulfoxide, phosphine, phosphite, phosphate, halide, and epoxy groups. Non-limiting examples of acrylic resins may include acrylic resins derived from: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, isooctyl methacrylate, isobornyl methacrylate, isodecanyl methacrylate, lauryl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, stearyl methacrylate, benzyl methacrylate, 2-phenoxyethyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, 3-methylphenyl methacrylate, 1-naphthyl methacrylate, 3-phenyl-n-propyl methacrylate, 2-phenyl-aminoethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, or combinations thereof.

[0026] The hydroxyl value of acrylic resins can range from 20 mg to 400 mg KOH / g (e.g., 30 mg to 350 mg KOH / g, 40 mg to 300 mg KOH / g, 50 mg to 250 mg KOH / g) and can represent acrylic polyols. The hydroxyl value can be determined according to DIN EN ISO 4629-1:2016. Non-limiting examples of acrylic polyols may include acrylic polyols derived from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, and 9-hydroxynonyl (meth)acrylate, derived from glycidyl (meth)acrylate-acid adducts, or traded under the name Cardura. TM E10 refers to acrylic polyols, or combinations thereof, derived from the glycidyl acrylate of neodecanoic acid, commercially available from Hexion Inc. (Columbus, USA), and their acrylic adducts. Suitable acrylic resins include, but are not limited to, those that can be trademarked. Acrylic resins (especially acrylic polyols) purchased from Allnex Germany GmbH (Germany), including but not limited to... 1776VS-65 1774SS-70 1797SS-70 1762 W-70, 1760 VB-64, 1795 VX-74, 91767 VX-60, DA 870 BA; and can be obtained under the trademark Acrylic resins commercially available from Allnex Germany GmbH (Germany), such as VIACRYL SC 370 / 75 SNA.

[0027] Suitable vinyl resins can be obtained by polymerizing one or more monomers comprising vinyl aromatic compounds, such as styrene and vinyltoluene; nitriles, such as (meth)acrylonitrile; vinyl and vinylidene halides, such as vinyl chloride and vinylidene fluoride; and vinyl esters, such as vinyl acetate. Suitable vinyl resins include, but are not limited to, those available under the trademark LUMIFLON TM Vinyl resins commercially available from AGC Chemicals Europe, Ltd. (Netherlands).

[0028] Suitable polyester resins can be obtained by condensation of a polyol and a polyacid or by ring opening polymerization of a lactone. As used herein, the term "polyol" refers to a compound having more than one hydroxyl group per molecule, for example containing 2, 3, 4, 5, 6, or more hydroxyl groups per molecule; and the term "polyacid" refers to a compound having more than one carboxylic acid group per molecule, for example containing 2, 3, 4, 5, 6, or more carboxylic acid groups per molecule, and includes the anhydrides of the corresponding acids. Suitable polyols include, but are not limited to, alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, polyethylene glycol having a molecular weight in the range of 200 g / mol to 10.000 g / mol, polypropylene glycol having a molecular weight in the range of 200 g / mol to 10.000 g / mol, polybutylene glycol having a molecular weight in the range of 300 g / mol to 10.000 g / mol, and neopentyl glycol; bisphenol A; hydrogenated bisphenol A; bisphenol F; hydrogenated bisphenol F; cyclohexanediol; propylene glycols such as 1,2-propanediol, 1,3-propanediol, butyl ethyl propylene glycol, 2-methyl-1,3-propanediol, and 2-ethyl-2-butyl-1,3-propanediol; butanediols such as 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 3-methyl-1,2-butanediol, and 2-ethyl-1,4-butanediol; pentanediols such as 1,2-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 3-methyl-4,5-pentanediol, and 2,2,4-trimethyl-1,3-pentanediol; hexanediols such as 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, and 2,5-hexanediol; poly(caprolactone) diols having a molecular weight in the range of 400 g / mol to 10.000 g / mol; polyether diols such as poly(oxytetramethylene) glycol; trimethylolpropane; pentaerythritol; dipentaerythritol; trimethylolethane; trimethylolbutane; dihydroxymethylcyclohexane; and glycerol. Suitable polyacids can include, but are not limited to, maleic acid; fumaric acid; itaconic acid; adipic acid; azelaic acid; succinic acid; sebacic acid; glutaric acid; phthalic acid; isophthalic acid; 5-tert-butyl isophthalic acid; tetrachlorophthalic acid; trimellitic acid; naphthalene dicarboxylic acid; naphthalene tetracarboxylic acid; terephthalic acid, hexahydrophthalic acid; methylhexahydrophthalic acid; dimethyl terephthalic acid; cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid; 1,4-cyclohexane dicarboxylic acid; tricyclodecane polycarboxylic acid, endomethylene tetrahydrophthalic acid; endoethylene hexahydrophthalic acid; cyclohexane tetracarboxylic acid; cyclobutane tetracarboxylic acid; and the anhydrides of all the above polyacids. Suitable lactones can include, but are not limited to, β-propiolactone; γ-butyrolactone; δ-valerolactone; ε-caprolactone; α-angelica lactone; and mixtures thereof. Suitable polyester resins include, but are not limited to, those available under the trademarks Polyester resins commercially available from Allnex Germany GmbH (Germany), such as 1715 VX-74, 91703 SS-53 and 91715 SS-55 and Uralac TM Polyester resins commercially available from DSM NeoResins (The Netherlands), such as Uralac TM SC-960 E-75, Uralac TM SY-942 F-65 and Uralac TM SY-943 E-75.

[0029] Suitable polyether resins can include, but are not limited to, polyalkylene ether polyols, such as poly(tetramethylene ether) glycol, polyethylene glycol, polypropylene glycol, and copolymers thereof. Polyether resins can be prepared by alkoxylating a polyol with an alkylene oxide, such as ethylene oxide, propylene oxide, and combinations thereof, in the presence of an acidic or basic catalyst. Non-limiting examples of suitable polyols can be the polyols described above for preparing polyester resins. In particular, suitable polyols can include, but are not limited to, bisphenol A, trimethylolpropane, pentaerythritol, glycerol, sorbitol, alkylene glycols, such as ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol, and combinations thereof. Poly(tetramethylene ether) glycol can be prepared by polymerizing tetrahydrofuran in the presence of a Lewis acid catalyst, such as boron trifluoride, tin(IV) chloride, antimony pentachloride, antimony trichloride, phosphorus pentafluoride, or sulfuryl chloride. Suitable polyether resins include, but are not limited to, those commercially available under the trademarks Polyether resins commercially available from Covestro (Germany), such as Desmoseal® 1150, Desmoseal® 1150 can be trademarked Desmoseal® 1150, Desmoseal® 1150 can be trademarked Desmoseal® Polyether resins commercially available from Covestro (Germany), such as Desmoseal® 1920 and Desmoseal® 1920 can be trademarked Desmoseal® 1920 and Desmoseal® 1920 can be trademarked Desmoseal® 550, and Desmoseal® 550 can be trademarked Desmoseal® Polyether resins commercially available from Lyondellbasell (Netherlands), such as Oxyplast® 1000. 1000.

[0030] Suitable polysiloxane resins can include, but are not limited to, alkyl-substituted polysiloxanes, aryl polysiloxanes, copolymers, blends, and mixtures thereof. The alkyl substituents can be selected from short chain alkyl groups having a carbon atom number of 1 to 4, such as methyl or propyl groups. The aryl substituents can include phenyl groups. Suitable polysiloxane resins include, but are not limited to, those commercially available under the trademarks 601 or M 50E, and DOWSIL RSN-6018, which are commercially available from Dow Chemical Company (USA) TM RSN-6018.

[0031] Suitable epoxy resins can be prepared by reacting a compound comprising at least one epoxide functional group and a cyclic co-reactant comprising at least two hydroxyl groups. Examples of suitable compounds comprising one epoxide functional group include, but are not limited to: glycidol; epichlorohydrin; glycidyl amine; and mixtures thereof. As used herein, the terms “epoxy” and “epoxide” are used interchangeably. Examples of suitable cyclic co-reactants comprising at least two hydroxyl groups include, but are not limited to: bisphenol A; hydrated bisphenol A; bisphenol F; hydrated bisphenol F; novolac resins, such as phenol novolac, cresol novolac; and mixtures thereof. Suitable epoxy resins include, but are not limited to: Eponex 1510, Eponex 1513, Epikote Resin 862, and Epikote Resin 828, which are commercially available from Hexion (USA); Epodil 757, which is commercially available from Evonik Corporation (Germany); Araldite GY 2600, Araldite GY 281, and Araldite EPN 1138, which are commercially available from Huntsman (USA).

[0032] Suitable polyurethane resins can be prepared by reacting a polyisocyanate and a polyol. As used herein, the term “polyisocyanate” refers to a compound having more than one isocyanate group per molecule, for example 2, 3, 4, 5, 6, or more isocyanate groups per molecule. Suitable polyisocyanates include aliphatic polyisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate; cycloaliphatic polyisocyanates such as isophorone diisocyanate and 4,4’-methylene-bis(cyclohexyl isocyanate); aromatic polyisocyanates such as 4,4’-diphenylmethane diisocyanate, toluene diisocyanate, 1,2,4-benzene triisocyanate, tetramethylxylylene diisocyanate, and polymethylene polyphenyl isocyanate. Non-limiting examples of suitable polyols can be the polyols described above for preparing polyester resins. Polyurethane resins can be prepared by reacting a polyisocyanate and a polyol (such as those described above) such that the OH / NCO equivalent ratio is greater than 1:1, such that free hydroxyl groups are present in the polyurethane resin, or such that the OH / NCO equivalent ratio is less than 1:1, such that free isocyanate groups are present in the polyurethane resin. In particular, polyurethane resins can be prepared by reacting a polyisocyanate and a polyol (such as those described above) such that the OH / NCO equivalent ratio is greater than 1:1, such that free hydroxyl groups are present in the polyurethane resin. The polyurethane resin can comprise hydroxyl groups or isocyanate groups, in particular hydroxyl groups. Suitable polyurethane resins include, but are not limited to a reaction product of Desmodur® N 3300 (commercially available from Covestro (Germany)) and an alkylene glycol such as ethylene glycol or propylene glycol.

[0033] Suitable polyamide resins can be prepared by polymerizing polyamines and polyacids or by ring-opening polymerization of lactams. In this document, the term "polyamine" refers to a compound having more than one amino group per molecule, for example, having 2, 3, 4, 5, 6, or more amino groups per molecule. Suitable polyamines include, but are not limited to, aliphatic diamines such as 1,2-ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,2-butanediamine, 1,3-butanediamine, 1,4-butanediamine, 1,3-pentanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 2-methyl-1,5-pentanediamine, 2,5-dimethylhexane-2,5-diamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-... -Decanediamine; alicyclic diamines, such as 2,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and 3,3'-diethyl-4,4'-diaminodicyclohexylmethane; and aromatic diamines, such as 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, 1,5-naphthylenediamine, 1,8-naphthylenediamine, 2,4-toluenediamine, 2,5-toluenediamine, 2,6-toluenediamine and 3,3'-dimethyl-4,4'-biphenylenediamine. Non-limiting examples of suitable polyacids may include those listed above for the preparation of polyesters. Suitable lactams may include, but are not limited to, β-propiolactam; γ-butyrolactam; δ-valerolactam; ε-caprolactam; and mixtures thereof. Suitable polyamide resins include, but are not limited to, those that may be branded Flex-Rez. TM Polyamide resins, such as Flex-Rez, are commercially available from Lawter (USA). TM 0080CS, Flex-Rez TM 1060CS, Flex-Rez TM 1074CS A.

[0034] The film-forming resin can be present in an amount of at least 25 wt.%, such as at least 30 wt.%, such as at least 40 wt.%, such as at least 50 wt.%, based on the total weight of solids in the coating composition. The film-forming resin can be present in an amount of no more than 95 wt.%, such as no more than 90 wt.%, such as no more than 85 wt.%, such as no more than 80 wt.%, based on the total weight of solids in the coating composition. The film-forming resin can be present in the coating composition in a range between any of the above-described values, such as 25 wt.% to 95 wt.%, such as 25 wt.% to 90 wt.%, such as 25 wt.% to 85 wt.%, such as 25 wt.% to 80 wt.%, such as 30 wt.% to 95 wt.%, such as 30 wt.% to 90 wt.%, such as 30 wt.% to 85 wt.%, such as 30 wt.% to 80 wt.%, such as 40 wt.% to 95 wt.%, such as 40 wt.% to 90 wt.%, such as 40 wt.% to 85 wt.%, such as 40 wt.% to 80 wt.%, such as 50 wt.% to 95 wt.%, such as 50 wt.% to 90 wt.%, such as 50 wt.% to 85 wt.%, such as 50 wt.% to 80 wt.%.

[0035] As used herein, the term "total solids" or "solids" or "solids content" refers to the solids content as determined in accordance with ASTM D2369 (2015).

[0036] The coating composition further comprises a crosslinking agent suitable for crosslinking the film-forming resin. As used herein, the term "crosslinking" refers to the formation of covalent bonds between polymer chains that make up a polymeric molecule. The terms "crosslinking agent," "curing agent," and "crosslinker" are used interchangeably herein. The curing or crosslinking reaction can be initiated, for example, by exposing the coating composition to heat or radiation, but can also proceed under ambient conditions to form a cured coating. The crosslinking agent can include at least one of a polyepoxide, a polyisocyanate, and an amino resin.

[0037] Suitable polyepoxides can include, but are not limited to, low molecular weight polyepoxides (e.g., polyepoxides having a molecular weight in the range of 200 g / mol to 500 g / mol) as well as higher molecular weight polyepoxides (e.g., polyepoxides having a molecular weight in the range of greater than 500 g / mol to 10.000 g / mol). Suitable low molecular weight polyepoxides include, but are not limited to, 3,4-epoxycyclohexylmethyl, 3,4-epoxycyclohexane carboxylate and bis(3,4-epoxy-6-methylcyclohexyl-methyl) adipate, bisphenol A diglycidyl ether, bisphenol E diglycidyl ether and bisphenol F diglycidyl ether. Suitable higher molecular weight polyepoxides can include, but are not limited to, polyglycidyl ethers of cyclic polyols, such as polyglycidyl ethers of polyhydric phenols (such as bisphenol A, bisphenol F, resorcinol, hydroquinone, benzene glycol, phloroglucinol and catechol); or polyglycidyl ethers of polyols, such as aliphatic polyols, in particular cycloaliphatic polyols, such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 2,2-bis(4-hydroxycyclohexyl)propane, 1,1-bis(4-hydroxycyclohexyl)ethane, 2-methyl-1,1-bis(4-hydroxycyclohexyl)propane, 2,2-bis(4-hydroxy-3-tert-butylcyclohexyl)propane, 1,3-bis(hydroxymethyl)cyclohexane and 1,2-bis(hydroxymethyl)cyclohexane. Examples of aliphatic polyols can include, but are not limited to, trimethylpentanediol and neopentyl glycol. Suitable polyepoxides include, but are not limited to, EPONEX TM 1510、 828、EPIKOTE TM Resin828.

[0038] Suitable polyisocyanates can be aliphatic, aromatic, or mixtures thereof. As used herein, the term "polyisocyanate" refers to compounds having at least two isocyanate groups per molecule, and includes monomeric polyisocyanates (such as monomeric diisocyanates), as well as dimers (uretdiones), trimers (isocyanurates), oligomers (formed, for example, from up to 15 monomeric polyisocyanates), allophanates, and polymers thereof, and is intended to include blocked polyisocyanates as well as unblocked polyisocyanates. Biurets can also be used. As used herein, the term "blocked polyisocyanate" refers to adducts derived from the equilibrium reaction of isocyanates with blocking agents, wherein the adducts are thermally unstable and dissociate (unblock) at elevated temperatures, such as temperatures above 120 °C. The term "unblocked isocyanate" refers to polyisocyanates without blocking agents. Polyisocyanates can be prepared from a variety of isocyanate-containing materials. Examples of suitable polyisocyanates include, but are not limited to, trimers prepared from toluene diisocyanate, 4,4'-methylene-bis(cyclohexyl isocyanate), isophorone diisocyanate, an isomeric mixture of 2,2,4- and 2,4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, tetramethylxylylene diisocyanate, and 4,4'- diphenylmethane diisocyanate. The isocyanate groups of the polyisocyanates can be blocked or unblocked as desired. Examples of suitable blocking agents include those materials that unblock at elevated temperatures, for example, at temperatures above 120 °C, such as lower aliphatic alcohols having from 1 to 6 carbon atoms, including methanol, ethanol, and n-butanol; cycloaliphatic alcohols, such as cyclohexanol; aromatic alkyl alcohols, such as benzyl alcohol and methylbenzyl alcohol; and phenolic compounds, such as phenol itself and substituted phenols, where the substituents do not affect the coating operation, such as cresol and nitrophenol. Glycol ethers can also be used as blocking agents. Suitable glycol ethers include ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol methyl ether, and propylene glycol methyl ether. Other suitable blocking agents include oximes, such as methyl ethyl ketoxime, acetone oxime, and cyclohexanone oxime; lactams, such as ε-caprolactam; pyrazoles, such as dimethylpyrazole; and amines, such as dibutylamine. Suitable polyisocyanates include, but are not limited to, those commercially available under the trademarks Desmodur® N 3400, Desmodur® N 3800, and Desmodur® N 3900 from Covestro (Germany), such as Desmodur® N 3400, Desmodur® N 3800, and Desmodur® N 3900 Desmodur® eco N 7300, Desmodur® Z 4470, Desmodur® N 3300, Desmodur® ultra DN, Desmodur® ultra N 3300, Desmodur® ultra IL EA, Desmodur® ultra N 3300 BA / SN, Desmodur® N 3400, Desmodur® N 3800, and Desmodur® N 3900 from Covestro (Germany), such as Desmodur® N 3400, Desmodur® N 3800, and Desmodur® N 3900 N 3900 and its mixtures.

[0039] Suitable amino resins can be obtained by the condensation reaction of an aldehyde (such as formaldehyde) with a compound containing at least two amine or amide groups per molecule. Suitable examples of aldehydes include, but are not limited to, formaldehyde, acetaldehyde, crotonaldehyde, and benzaldehyde. Suitable examples of compounds containing at least two amine or amide groups include, but are not limited to, melamine, urea, and phenylmelamine. Suitably, amino resins can generally be etherified with an alcohol (such as methanol, ethanol, butanol, or mixtures thereof). Suitable amino resins include, but are not limited to, those commercially available from Prefere Resin Holding GmbH (Germany). Amino resins, such as MF 612 / 70B MF 613 / 71B and MF 650 / 55IB, available from Allnex Industries (Germany). Amino crosslinking agents, such as 303 202 1161、 325 and 1133; Available for purchase from Allnex (Germany) Amino resins, such as US-138BB-70 and US-146BB-72.

[0040] The crosslinker can be present in an amount of at least 5 wt.%, such as at least 10 wt.%, such as at least 15 wt.%, such as at least 20 wt.%, based on the total weight of solids in the coating composition. The crosslinker can be present in an amount of not more than 75 wt.%, such as not more than 70 wt.%, such as not more than 60 wt.%, such as not more than 50 wt.%, based on the total weight of solids in the coating composition. The crosslinker can be present in the coating composition in a range of any of the above values, such as 5 wt.% to 75 wt.%, such as 5 wt.% to 70 wt.%, such as 5 wt.% to 60 wt.%, such as 5 wt.% to 50 wt.%, such as 10 wt.% to 75 wt.%, such as 10 wt.% to 70 wt.%, such as 10 wt.% to 60 wt.%, such as 10 wt.% to 50 wt.%, such as 15 wt.% to 75 wt.%, such as 15 wt.% to 70 wt.%, such as 15 wt.% to 60 wt.%, such as 15 wt.% to 50 wt.%, such as 20 wt.% to 75 wt.%, such as 20 wt.% to 70 wt.%, such as 20 wt.% to 60 wt.%, such as 20 wt.% to 50 wt.%.

[0041] The coating composition can further include a solvent or mixture of solvents. Suitable solvents include organic solvents and mixtures thereof. The organic solvents can include any suitable organic solvent known in the art. Non-limiting examples of suitable organic solvents can include, but are not limited to, alcohols, glycol ethers, esters, ether esters and ketones, aliphatic and / or aromatic hydrocarbons, and mixtures thereof, such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, 2-butyl alcohol, tridecanol, 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, n-butyl acetate, diethylene glycol butyl ether acetate, acetone, xylene, toluene, solvent naphtha, and mixtures thereof. The solvent can be present in an amount of at least 5 wt.%, such as at least 10 wt.%, such as at least 15 wt.%, such as at least 20 wt.%, such as 30 wt.%, based on the total weight of the coating composition. The solvent can be present in an amount of no more than 70 wt.%, such as no more than 65 wt.%, such as no more than 60 wt.%, such as no more than 55 wt.%, such as no more than 50 wt.%, based on the total weight of the coating composition. The solvent can be present in a range between any of the above-described values, such as 5 wt.% to 70 wt.%, such as 5 wt.% to 65 wt.%, such as 5 wt.% to 60 wt.%, such as 5 wt.% to 55 wt.%, such as 5 wt.% to 50 wt.%, such as 10 wt.% to 70 wt.%, such as 10 wt.% to 65 wt.%, such as 10 wt.% to 60 wt.%, such as 10 wt.% to 55 wt.%, such as 10 wt.% to 50 wt.%, such as 15 wt.% to 70 wt.%, such as 15 wt.% to 65 wt.%, such as 15 wt.% to 60 wt.%, such as 15 wt.% to 55 wt.%, such as 15 wt.% to 50 wt.%, such as 20 wt.% to 70 wt.%, such as 20 wt.% to 65 wt.%, such as 20 wt.% to 60 wt.%, such as 20 wt.% to 55 wt.%, such as 20 wt.% to 50 wt.%, such as 30 wt.% to 70 wt.%, such as 30 wt.% to 65 wt.%, such as 30 wt.% to 60 wt.%, such as 30 wt.% to 55 wt.%, such as 30 wt.% to 50 wt.% in the coating composition.

[0042] The coating composition can be a solvent-borne coating composition. As used herein, the term "solvent-borne coating composition" means a coating composition that is a liquid at room temperature (23 °C) and at atmospheric pressure (101.3 kPa) and that includes one or more organic solvents as a major component of the liquid carrier and less than 50 wt.% water, such as less than 40 wt.% water, such as less than 30 wt.% water, such as less than 20 wt.% water, such as less than 10 wt.% water, such as less than 5 wt.% water, such as less than 2 wt.% water, such as less than 1 wt.% water, based on the total weight of the liquid carrier (i.e., the combination of organic solvents and water, if present). The solvent-borne coating composition can be substantially free of water, i.e., the solvent-borne coating composition can include less than 0.5 wt.% water, such as less than 0.2 wt.% water, such as less than 0.1 wt.% water, based on the total weight of the liquid carrier. The solvent-borne coating composition can be completely free of water, i.e., the solvent-borne coating composition can include 0 wt.% water, based on the total weight of the liquid carrier.

[0043] The coating composition can be a multi-component coating composition, such as a two-component (2K) coating composition. As used herein, the terms "multi-component," "multi-K," and "multi-pack" mean a coating composition that includes a first component that can include a film-forming resin, a second component that can include a crosslinker, and an optional additional component that can or can not include a film-forming resin or a crosslinker, where the components are kept separate until just prior to use. When the multi-component coating composition does not include an additional component, it is a two-component (2K) coating composition.

[0044] The coating composition can be a clear coating composition. As used herein, the term "clear coating composition" means a coating composition that, upon drying and / or curing, provides a coating that is at least substantially transparent or completely transparent and can not include a colorant. The term "colorant" means any substance that imparts color and / or other opacity and / or other visual effect to the composition. The term "substantially transparent" means a coating in which, when viewed through the coating, at least part of the surface beyond the coating is visible to the naked eye. The term "completely transparent" means a coating in which, when viewed through the coating, the entire surface beyond the coating is visible to the naked eye. The clear coating can be substantially free of pigments. Substantially free of pigments can refer to a "tinted clear coating," which can be a coating composition that includes less than 3 wt.% pigments, such as less than 2 wt.%, less than 1 wt.% or 0 wt.% pigments, based on total solids.

[0045] As used herein, the term "pigment" means an organic or inorganic material or a combination thereof that can be a colored material that is completely or nearly insoluble in the solvent of the coating composition, i.e., less than 10 mg of the material will dissolve in 1 L of the solvent at room temperature.

[0046] Alternatively, the coating composition can include a colorant. The colorant can be added to the coating composition in any suitable form, such as discrete particles, dispersions, solutions, and / or flakes. Examples of suitable pigments include, but are not limited to, carbazole dioxazine pigments, azo pigments, monoazo pigments, disazo pigments, naphthol AS pigments, lake-type (lake) pigments, benzimidazolone pigments, metal complex pigments, isoindolinone pigments, isoindoline pigments, polycyclic phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, diketopyrrolopyrrole pigments, thioindigo pigments, anthraquinone pigments, indanthrone pigments, anthrapyrimidine pigments, flavanthrone pigments, pyranthrone pigments, anthraquinonperinone pigments, dioxazine pigments, triarylcarbonium pigments, quinophthalone pigments, diketopyrrolopyrrole red (“DPPBO red”), titanium dioxide, carbon black, and mixtures thereof. Suitable dyes include, but are not limited to, acid dyes, azo dyes, basic dyes, direct dyes, disperse dyes, reactive dyes, solvent dyes, sulfur dyes, mordant dyes, for example, bismuth vanadate, anthraquinone, perylene, aluminum, quinacridone, thiazole, thiazine, azo, indigoid, nitro, nitroso, oxazine, phthalocyanine, quinoline, stilbene, and triphenylmethane.

[0047] The film-forming resin present in the coating composition can include an acrylic polyol resin, a polyester resin, a polyether resin, a polyurethane resin, or a combination thereof. Suitable acrylic polyol resins, polyester resins, polyether resins, and polyurethane resins can be selected from any of those described above.

[0048] The crosslinking agent present in the coating composition can include a polyisocyanate. Suitable polyisocyanates can be selected from any of those described above.

[0049] The coating composition can further include an ultraviolet light absorber, a hindered amine light stabilizer, a catalyst, a rheology modifier, a sag control agent, a scratch and mar resistance additive, an antifoam additive, a leveling additive, or any combination thereof.

[0050] As used herein, the term “ultraviolet light absorber” refers to a compound used to absorb ultraviolet radiation, for example, in order to reduce ultraviolet degradation of a polymeric material as compared to the same polymeric material that does not include the compound. Examples of suitable ultraviolet light absorbers include, but are not limited to, CYASORB UV Stabilizers available from Solvay (Netherlands), such as CYASORB UV-1164L; and TINUVIN® UV absorbers available from BASF (Germany). 1130.

[0051] As used herein, the term "hindered amine light stabilizer" refers to a compound comprising an amine functional group that is added to a polymeric material to inhibit or retard degradation of the material by, for example, photo-oxidation, as compared to the same composition without the compound. Typically, a derivative of tetramethylpiperidine is used. Examples of suitable hindered amine light stabilizers include, but are not limited to, CHIMASSORB® 944, CHIMASSORB® 2020, and CHIMASSORB® 119, available from BASF (Germany). light stabilizers, such as 292、 123、 328、 622、 783 and 770.

[0052] As used herein, the term "catalyst" refers to a catalyst that promotes any desired curing reaction. Any catalyst that is typically used to catalyze crosslinking reactions can be used, and there is no particular limitation on the catalyst. Non-limiting examples of catalysts include, but are not limited to, phenyl acid phosphate, sulfonic acid functional catalysts such as dodecylbenzenesulfonic acid (DDBSA), dinonylnaphthalene sulfonic acid, dinonylnaphthalene disulfonic acid, salts of the aforementioned sulfonic acids; complexes of organometallic compounds comprising tin, zinc, zirconium, strontium, or bismuth, such as stannous octoate, butyl tin acid, dibutyl tin dilaurate (DBTL), dibutyl tin diacetate, dibutyl tin mercaptide, dibutyl tin diacetate, dibutyl tin dimaleate, dimethyl tin diacetate, dimethyl tin dilaurate; 1,4-diazabicyclo[2.2.2]octane; bismuth carboxylate, and the like; tertiary amines such as 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylamine, and the like; or any combination of the foregoing catalysts.

[0053] Alternatively, the coating composition can be substantially free of catalyst. The term "substantially free of" as used throughout this specification refers to a composition comprising less than 0.5 wt.%, such as 0.2 wt.%, such as 0.1 wt.% of the respective compound, based on the total weight of the coating composition, unless otherwise specified. The coating composition can be completely free of catalyst, i.e., the coating composition can comprise 0 wt.% of catalyst.

[0054] As used herein, "rheology modifier" refers to a component that adjusts the flow behavior of a composition by increasing the viscosity of the composition with which it is in contact, as compared to the same composition not in contact with the rheology modifier. Non-limiting examples of rheology modifiers include silica, chemically modified silica (e.g., fumed silica), alumina, chemically modified alumina (e.g., fumed alumina), hectorite clay (e.g., bentonite), hydrophobically modified ethylene oxide polymers, rubber latex (e.g., particles of styrene-butadiene rubber dispersed in an aqueous liquid medium), cellulose derivatives, polyamide waxes, microgels, solvent-borne polymer-based associative thickeners (e.g., RHEOBYK-410, RHEOBYK 415; RHEOBYK 430, and RHEOBYK 431, commercially available from BYK-Chemie GmbH (Germany); AQUA-CHEM® 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, and 10000, commercially available from BASF SE (Germany); and RM 1463; and ), or any combination thereof.

[0055] As used herein, the term "sag control agent" refers to a compound that minimizes sag (i.e., defects such as tears caused by gravity-driven flow of a wet coating composition) when applied to a substrate, particularly a substrate comprising a non-horizontal (e.g., vertical) surface, as compared to the same wet coating composition not comprising a sag control agent. Suitable flow control agents, and in particular sag control agents, can include, but are not limited to, the compounds described in US 4,311,622 A, EP 0 192 304 A1, and EP 3 728 482 A1.

[0056] As used herein, the term "scratch and mar resistant additive" refers to a compound that reduces degradation of a film formed from a coating composition after mechanical impact to the film, as compared to degradation of a film formed from the same coating composition not comprising the compound. For example, a scratch and mar resistant additive can help to create a sacrificial layer, reduce the surface tension of the film, introduce material that protrudes above the surface of the film, or combinations thereof. Suitable scratch and mar resistant additives include, but are not limited to, waxes, including natural, synthetic, mineral hydrocarbon, and petroleum waxes; silicone-based agents, fluoro-based and polytetrafluoroethylene-based agents; silicas, including colloidal silica; and metal oxides, including aluminum oxide. Examples of scratch and mar resistant additives include NANOBYK-3650 and NANOBYK-3652, commercially available from BYK-Chemie GmbH (Germany).

[0057] As used herein, the term "defoaming additive" refers to an additive that reduces and hinders the formation of foam in a fluid coating composition during its manufacture, handling, and use. The terms anti-foam agent and defoamer are generally used interchangeably. Suitable defoaming additives include, but are not limited to, oils that are insoluble in the solvent of the coating composition (i.e., less than 1 mg of material will dissolve in 1 L of solvent at room temperature), polydimethylsiloxanes and other silicones, stearates, and glycols. Examples of additives with defoaming properties include, among others, BYK-390 commercially available from BYK-Chemie GmbH (Germany).

[0058] As used herein, the term "leveling agent" refers to a compound that enhances the thickness uniformity of a cured coating as compared to a coating formed from the same composition that does not include the agent. Suitable leveling agents that can be used include, but are not limited to, BYK-320 or BYK-306 commercially available from BYK-Chemie GmbH (Germany).

[0059] Substrates to which the protective coating composition can be applied include a variety of substrates. For example, the protective coating composition can be applied to a vehicle substrate, an industrial substrate, an aerospace substrate, and the like.

[0060] As non-limiting examples, the substrate can include a polymer or composite material, such as a fiberglass composite material. Vehicle components, typically formed from thermoplastic and thermoset materials, include bumpers, trim, and other rigid and flexible plastics, including fiberglass, sheet molding compound (SMC), polycarbonate, thermoplastic polyolefin (TPO), rubber, and similar materials. As non-limiting examples, the substrate can be a portion of a bumper, a spoiler, a wheel cover, a door handle, a plastic clad door, a marine vessel, a motorcycle, a hood, a body panel, and a building cladding, such as a sign or a logo for a building.

[0061] Non-limiting examples of substrates to which the protective coating composition can be applied include rigid metal substrates, such as ferrous metals, aluminum, aluminum alloys, copper, and other metal and alloy substrates. Ferrous metal substrates can include iron, steel, and alloys thereof. Non-limiting examples of useful steel materials include cold rolled steel, galvanized (zinc-coated) steel, electrogalvanized steel, stainless steel, pickled steel, zinc-iron alloys, and combinations thereof. Combinations or composites of ferrous and non-ferrous metals can also be used.

[0062] Non-limiting examples of steel substrates, such as cold rolled steel or any of the steel substrates listed above, include those coated with a weldable, zinc-rich or iron phosphide-rich organic coating. Cold rolled steel can also be suitable when pretreated with a suitable solution known in the art, such as a metal phosphate solution, an aqueous solution containing a Group IIIB or Group IVB metal, an organic phosphate solution, an organic phosphonate solution, and combinations thereof, as described below. Non-limiting examples of aluminum alloys include those used in the automotive or aerospace industries, such as 2000, 6000, or 7000 series aluminum; 2024, 7075, 6061 are specific examples. The alloys can be unclad, or they can include a cladding layer on the surface composed of a different aluminum alloy than the underlying / base body alloy.

[0063] Non-limiting examples of substrates include more than one metal or metal alloy, where the substrate can be a combination of two or more metal substrates assembled together, such as a hot-dipped galvanized steel assembled with an aluminum substrate.

[0064] Non-limiting examples of shapes of metal substrates include in the form of a sheet, plate, rod, bar, or any desired shape, but in many cases it can be in the form of an automotive part, such as a vehicle body, a vehicle door, a trunk lid, a fender, a hood, or a bumper. The thickness of the substrate can vary as desired.

[0065] Non-metallic substrates include, but are not limited to, polymeric substrates such as polyesters, polyolefins, polyamides, cellulose, polystyrene, polyacrylic, poly(ethylene naphthalate), polymethacrylate, polypropylene, polyethylene, nylon, ethylene-vinyl alcohol (EVOH), polylactic acid (PLA), other “green” polymeric substrates, poly(ethylene terephthalate) (PET), polycarbonate, polycarbonate acrylonitrile butadiene styrene copolymer (PC / ABS), polyamide, and / or plastic composite substrates such as glass or carbon fiber composites. Non-metallic substrates can include wood, veneer, wood composites, particle board, medium density fiberboard, cement, stone, glass, paper, cardboard, textiles, synthetic and natural leathers, and the like. The protective coating composition can be applied directly to plastics, flame-treated plastic surfaces, plastics having an adhesion promoter applied thereon, and / or primed plastics.

[0066] The above-described coating compositions can be applied over a portion of a substrate, such as those described above, having an existing coating on the surface of the substrate, and then the above-described coating compositions are applied to the existing coating by the methods described herein. The existing coating can be a single layer or a multi-layer coating that has been cured, such as, but not limited to, a cured multi-layer coating comprising a primer, a basecoat, and a topcoat, such as a clearcoat. These layers can be formed from coating compositions known in the art, and can be applied and cured by various methods known in the art. As non-limiting examples, the coatings used to form these layers of the existing cured coating can be waterborne or solvent-based coatings, powder coatings, and / or electro-deposition coatings known in the art. These coatings can be applied using, for example, conventional brushing, rolling, spraying, powder, and electro-coating techniques, but are not limited thereto, and can be cured using, for example, convection curing, infrared curing (both continuous and pulsed infrared curing as defined herein), or ultraviolet curing, but are not limited thereto.

[0067] As used herein, the term "primer" means a coating that can be applied to a substrate, including bare substrates, to prepare a surface for the application of a protective or decorative coating composition.

[0068] As used herein, the term "basecoat" means a coating applied over a primer, another basecoat layer; and / or a coating applied directly to a substrate, which coating optionally contains components that affect color and / or provide other visual effects (e.g., colorants as described above).

[0069] The above-described coating compositions can be applied as the outermost layer over an existing cured clearcoat layer.

[0070] The methods disclosed herein make it possible to apply the above-described coating compositions only over a portion of the surface of a substrate without the need to mask those portions of the surface that are not to be coated with the composition with a removable material, such as a tape material.

[0071] In the present methods, the coating composition can be applied as a continuous jet, as a continuous stream of droplets, and / or as drop-on-demand. As used herein, the term "continuous jet" means a continuous stream of coating composition exiting a precision applicator that is applied to a substrate to provide a knife edge at the termination of the applied coating. As used herein, the terms "drop" and "droplet" mean a column of liquid completely bounded by a free surface. As used herein, the term "continuous stream of droplets" means a plurality of droplets of coating exiting a precision applicator that are applied far enough apart to reduce the volume of material applied compared to a continuous jet, but close enough together to flow together and provide a conformal coating coverage. As used herein, "drop-on-demand" means a precision applicator that controls the volume of individual drops and dispenses such drops only when instructed to do so.

[0072] In the present method, the above-mentioned coating composition is cured by applying pulsed infrared radiation having a peak wavelength in the range of 3 μm to 10 μm to the coating composition with a pulse duration of less than 100 μs, which coating composition is applied to at least a portion of the surface of a substrate.

[0073] As used herein, the term "peak wavelength" refers to the maximum emission wavelength of the pulsed infrared radiation. The pulsed infrared radiation used in the present method can have a peak wavelength of 6 μm or less, or 4 μm or less. The pulsed infrared radiation can be in the range of 3 μm to 6 μm, or 3 μm to 4 μm.

[0074] As used herein, the term "pulsed" refers to radiation that is emitted in a timed portion (pulse). The term "infrared radiation" refers to electromagnetic radiation having a wavelength in the range of 780 nm to 1 mm. Thus, the term "pulsed infrared radiation" refers to electromagnetic radiation having a wavelength in the infrared spectral range, which is applied in the form of pulses. The pulses can have a pulse duration at a pulse frequency.

[0075] As used herein, the term "pulse duration" (also referred to as "pulse width") refers to the full width at half maximum (FWHM) amplitude of the pulse of the pulsed infrared radiation. The pulsed infrared radiation can be applied with a pulse duration of at least 5 μs, such as at least 7 μs, or at least 8 μs, or at least 10 μs. The pulsed infrared radiation can be applied with a pulse duration of 75 μs or less, such as 50 μs or less, or 25 μs or less, or 17 μs or less, or 14 μs or less. The pulsed infrared radiation can be applied with a pulse duration in the range of 7 μs to 14 μs, or 8 μs to 14 μs, or 10 μs to 14 μs, or 7 μs to 17 μs, or 8 μs to 17 μs, or 10 μs to 17 μs, or 7 μs to 25 μs, or 8 μs to 25 μs, or 10 μs to 25 μs, or 7 μs to 50 μs, or 8 μs to 50 μs, or 10 μs to 50 μs, or 7 μs to 75 μs, or 8 μs to 75 μs, or 10 μs to 75 μs. The pulsed infrared radiation can be applied with a pulse duration in a range between any of the above-mentioned values, such as in the range of 7 μs to 75 μs, such as 7 μs to 50 μs, such as 8 μs to 25 μs, such as 10 μs to 17 μs, such as 10 μs to 14 μs.

[0076] The term "cure," "cured," or like terms as used in connection with the coating composition described herein means that at least a portion of the components forming the coating composition are crosslinked to form a coating layer. Pulsed infrared radiation can be applied to the coating composition to form an at least partially cured coating layer. As used herein, the term "at least partially cured coating layer" means that at least a portion of the reactive groups of the components of the coating composition have reacted. Pulsed infrared radiation can be applied to the coating composition to form a fully cured coating layer. Full cure is reached when further curing does not result in a significant further improvement in the properties of the coating layer. Cure or degree of cure can also be determined by dynamic mechanical thermal analysis (DMTA) using a Polymer Laboratories MKIIIDMTA analyzer under nitrogen, where the degree of cure can be, for example, at least 10%, such as at least 30%, such as at least 50%, such as at least 70%, or at least 90% of full crosslinking as determined by DMTA.

[0077] The coating composition can be cured by applying pulsed infrared radiation for a total time of up to or less than 10 min, or up to or less than 5 min, or up to or less than 3 min. The coating composition can be cured by applying pulsed infrared radiation for a total time of at least 30 sec, or at least 1 min, or at least 2 min. The total time for curing the coating composition by applying pulsed infrared radiation can range between any of the above values. For example, the coating composition can be cured by applying pulsed infrared radiation for a total time of 30 sec to 10 min, or 30 sec to 5 min, or 1 min to 3 min. As used herein, the term "total time for curing the coating composition by applying pulsed infrared radiation" refers to the entire time that pulsed radiation is applied, including both the pulse on and pulse off states. Shorter curing times can be achieved compared to oven curing, resulting in energy savings. This method also provides high efficiency because the infrared radiator is active shortly after being turned on, without the need for a long pre-heat period, and only heats the desired portion of the area, e.g., the substrate to which the coating composition has been applied.

[0078] Without wishing to be bound by a particular theory, the transfer of energy to the coating composition using pulsed infrared radiation is not achieved primarily by thermal convection or thermal conduction, but by invisible electromagnetic waves in the infrared spectrum range that travel at the speed of light, as electromagnetic waves propagate at the same speed and in the same way as light waves. The infrared radiation penetrates rapidly and efficiently to the surface of the substrate and ensures that the applied coating composition cures rapidly. This enables the transfer of radiation with a high energy density and thus enables the efficient use of energy for curing the coating. In comparison to thermal methods, even when curing a coating with a thickness of 75 pm or more, faster and more energy-efficient curing can be achieved at a rather low surface temperature of the substrate (e.g. below 130 °C) and even lower temperatures within the bulk of the substrate. In combination with precision application, this effectively prevents flow and sagging of the applied coating composition. In addition to accelerating curing, the use of pulsed infrared can impart enhanced physical and / or chemical properties to the cured coating formed from the coating composition described above.

[0079] The enhanced physical and / or chemical properties can include at least one of the following: microhardness, scratch and mar resistance, chemical resistance to at least one of an acid, an enzyme, and tree sap, or a combination thereof. As used herein, the term “microhardness” refers to the resistance of a material to undergo permanent deformation when a low force (e.g. a force in the range of 0.01 N to 10 N) is applied. Microhardness can be determined according to DIN EN ISO 14577-1. As used herein, the term “scratch and mar resistance” refers to the resistance of a material to damage by impacts, rubs, or abrasions that produce visible scratches or abrasions. Scratch and mar resistance can be determined according to DIN EN ISO 20566:2021 and DIN EN ISO 21546:2021. As used herein, the term “chemical resistance” refers to the resistance of a material to the effects of chemicals, such as discoloration, change in gloss, softening, swelling, coating flaking, or blistering. Chemical resistance to at least one of an acid, an enzyme, and tree sap, or a combination thereof can be determined according to DIN EN ISO 2812-5:2018.

[0080] The surface temperature of the substrate during the application of pulsed infrared radiation to the applied coating composition to form the cured coating can be less than 130 °C or less than 120 °C. The surface temperature of the substrate during the application of pulsed infrared radiation in step (ii) to the applied coating composition to form the cured coating can be at least 90 °C. The surface temperature of the substrate during the application of pulsed infrared radiation to the applied coating composition to form the cured coating can be in the range of 90 °C to 130 °C, such as 90 °C to 120 °C. The surface temperature of the substrate can be determined according to DIN EN 60584-1 :2016.

[0081] The pulsed infrared radiation can be applied at a pulse frequency of at least 350 Hz, such as at least 370 Hz, or at least 390 Hz, or at least 400 Hz. The pulsed radiation can be applied at a pulse frequency of 450 Hz or less, such as 430 Hz. The pulsed infrared radiation can be applied at a pulse frequency in a range of 350 Hz to 450 Hz, such as 350 Hz to 430 Hz, or 370 Hz to 450 Hz, or 370 Hz to 430 Hz, or 390 Hz to 450 Hz, or 390 Hz to 430 Hz, or 400 Hz to 450 Hz, or 400 Hz to 430 Hz. The pulsed infrared radiation can be applied at a pulse frequency in a range of 350 Hz to 450 Hz, such as 370 Hz to 450 Hz, such as 390 Hz to 430 Hz, such as 390 Hz to 430 Hz. As used herein, the term "pulse frequency" refers to the number of pulses per second of the pulsed infrared radiation.

[0082] The pulsed infrared radiation can be applied at a pulse energy of at least 250 W / cm 2 , such as at least 270 W / cm 2 , or at least 290 W / cm 2 . The pulsed radiation can be applied at a pulse energy of 350 W / cm 2 or less, such as 330 W / cm 2 or less, or 320 W / cm 2 or less. The pulsed infrared radiation can be applied at a pulse energy in a range between any of the above values, such as in a range of 250 W / cm 2 to 350 W / cm 2 , or 250 W / cm 2 to 330 W / cm 2 , or 250 W / cm 2 to 320 W / cm 2 , or 270 W / cm 2 to 350 W / cm 2 , or 270 W / cm 2 to 330 W / cm 2 , or 270 W / cm 2 to 320 W / cm 2 , or 290 W / cm 2 to 350 W / cm 2 , or 290 W / cm 2 to 330 W / cm 2 , or 290 W / cm 2 to 320 W / cm 2 . As used herein, the term "pulse energy" refers to the total radiant power of electromagnetic radiation received by each unit area of surface.

[0083] The pulsed infrared radiation can be provided by an infrared light source comprising a surface comprising a ceramic composition. The ceramic composition can be capable of absorbing heat and emitting infrared radiation having a peak wavelength in the range of 3 pm to 10 pm. The infrared light source can comprise a surface comprising a ceramic composition capable of absorbing heat and emitting infrared radiation having a peak wavelength in the range of 3 pm to 10 pm.

[0084] For curing, the infrared radiation emitting surface of the infrared light source can face the surface of the substrate to which the coating composition to be cured has been applied. Herein, the distance between the infrared emitting surface of the infrared light source and the surface of the substrate to which the coating composition to be cured has been applied can be a distance of at least 5 cm, such as at least 10 cm, or at least 15 cm. Herein, the distance between the infrared emitting surface of the infrared light source and the surface of the substrate to which the coating composition to be cured has been applied can be 50 cm or less, such as 45 cm or less, or 40 cm or less, or 35 cm or less, or 30 cm or less, or 25 cm or less. The infrared radiation emitting surface of the infrared light source can face the surface of the substrate to which the coating composition to be cured has been applied at a distance in the range between any of the above values, such as in the range of 5 cm to 50 cm, such as 5 cm to 45 cm, such as 5 cm to 40 cm, such as 5 cm to 35 cm, such as 5 cm to 30 cm, such as 5 cm to 25 cm, such as 10 cm to 50 cm, such as 10 cm to 45 cm, such as 10 cm to 40 cm, such as 10 cm to 35 cm, such as 10 cm to 30 cm, such as 10 cm to 25 cm, such as 15 cm to 50 cm, such as 15 cm to 45 cm, such as 15 cm to 40 cm, such as 15 cm to 35 cm, such as 15 cm to 30 cm, such as 15 cm to 25 cm.

[0085] The infrared light source can face the surface of the substrate to which the coating composition to be cured has been applied at least from one side. The at least one or more infrared light sources can surround the substrate to which the coating composition to be cured has been applied at least from one side. Suitable arrangements of the infrared light source are described, for example, in EP 1 690 842 A1 (in particular in paragraphs

[0044] to

[0049] ) and WO 2011 / 015164 (in particular on page 12 and page 13), the specific disclosures of which are incorporated herein by reference. The infrared light source can have any desired shape, such as a rod shape, a tube shape, a flat plate shape, or a curved plate shape.

[0086] The infrared light source can further comprise a heat source for directly or indirectly heating the ceramic composition. The heat transfer from the heat source can comprise various heat transfer means, including radiative transfer, convection, contact transfer or transfer via a thermally conductive material between the heat source and the ceramic composition. The infrared light source can further comprise a carrier material for heat absorption and / or heat transfer from the heat source to the ceramic composition. The carrier material can comprise one or more of the following materials: Fe; Si02; 3Al203-2Si02and / or 2Al203-Si02(mullite); Al or Cu. Further, the infrared light source can comprise a reflector device. The ceramic composition can generate infrared light and emit the infrared light in unwanted directions. A reflector device, which can comprise one or more reflectors, can be applied to reflect the infrared light emitted in unwanted directions and redirect the infrared light in a certain area, for example, to the surface of a substrate to which a coating composition to be cured has been applied.

[0087] The ceramic composition can comprise (a) a metal oxide component comprising (a-i) at least one metal element selected from the group consisting of alkaline earth elements, transition metal elements, lanthanide series elements and actinide series elements, and (a-ii) oxygen; and (b) a mullite remainder component comprising 3Al203-2Si02and / or 2Al203-Si02(mullite). Suitable examples of the metal oxide component (a) include, but are not limited to, Cr203, Zr02, Ho203, Fe203, LaCr03, Ce02, Y203, YCr03, Gd203, MgAl204, MgCr04, CaCr04, YCr03, CuO, La203, CuCr04and FeCr03.

[0088] The ceramic composition can consist of the metal oxide component (a) and the mullite remainder component (b).

[0089] The ceramic composition can comprise at least 0.1 wt.% of the metal oxide component (a), such as at least 0.5 wt.%, such as at least 1.0 wt.%, such as at least 5.0 wt.%, based on the total weight of the ceramic composition. The ceramic composition can comprise 70.0 wt.% or less of the metal oxide component (a), such as 60.0 wt.% or less, such as 50.0 wt.% or less, such as 40.0 wt.% or less, such as 30.0 wt.% or less, such as 20.0 wt.% or less, based on the total weight of the ceramic composition. The ceramic composition can comprise the metal oxide component (a) in a range of 0.1 wt.% to 70.0 wt.%, or 0.5 wt.% to 70.0 wt.%, or 1.0 wt.% to 70.0 wt.%, or 5.0 wt.% to 70.0 wt.%, or 0.1 wt.% to 60.0 wt.%, or 0.5 wt.% to 60.0 wt.%, or 1.0 wt.% to 60.0 wt.%, or 5.0 wt.% to 60.0 wt.%, or 0.1 wt.% to 50.0 wt.%, or 0.5 wt.% to 50.0 wt.%, or 1.0 wt.% to 50.0 wt.%, or 5.0 wt.% to 50.0 wt.%, or 0.1 wt.% to 40.0 wt.%, or 0.5 wt.% to 40.0 wt.%, or 1.0 wt.% to 40.0 wt.%, or 5.0 wt.% to 40.0 wt.%, or 0.1 wt.% to 30.0 wt.%, or 0.5 wt.% to 30.0 wt.%, or 1.0 wt.% to 30.0 wt.%, or 5.0 wt.% to 30.0 wt.%, or 0.1 wt.% to 20.0 wt.%, or 0.5 wt.% to 20.0 wt.%, or 1.0 wt.% to 20.0 wt.%, or 5.0 wt.% to 20.0 wt.%, based on the total weight of the ceramic composition. The ceramic composition can comprise the metal oxide component (a) in a range of 0.1 wt.% to 70.0 wt.%, such as 0.5 wt.% to 60.0 wt.%, such as 0.5 wt.% to 50.0 wt.%, such as 1.0 wt.% to 40.0 wt.%, such as 1.0 wt.% to 30.0 wt.%, such as 5.0 wt.% to 20.0 wt.%, based on the total weight of the ceramic composition.

[0090] The ceramic composition can comprise at least 30.0 wt.% of the mullite remainder component (b), such as at least 40.0 wt.%, such as at least 50.0 wt.%, such as at least 60.0 wt.%, such as at least 70.0 wt.%, such as at least 80.0 wt.%, based on the total weight of the ceramic composition. The ceramic composition can comprise 99.9 wt.% or less of the mullite remainder component (b), such as 99.5 wt.% or less, such as 99.0 wt.% or less, such as 95.0 wt.% or less, based on the total weight of the ceramic composition. The ceramic composition can comprise the mullite remainder component (b) in a range of 30.0 wt.% to 99.9 wt.%, or 30.0 wt.% to 99.5 wt.%, or 30.0 wt.% to 99.0 wt.%, or 30.0 wt.% to 95.0 wt.%, or 40.0 wt.% to 99.9 wt.%, or 40.0 wt.% to 99.5 wt.%, or 40.0 wt.% to 99.0 wt.%, or 40.0 wt.% to 95.0 wt.%, or 50.0 wt.% to 99.9 wt.%, or 50.0 wt.% to 99.5 wt.%, or 50.0 wt.% to 99.0 wt.%, or 50.0 wt.% to 95.0 wt.%, or 60.0 wt.% to 99.9 wt.%, or 60.0 wt.% to 99.5 wt.%, or 60.0 wt.% to 99.0 wt.%, or 60.0 wt.% to 95.0 wt.%, or 70.0 wt.% to 99.9 wt.%, or 70.0 wt.% to 99.5 wt.%, or 70.0 wt.% to 99.0 wt.%, or 70.0 wt.% to 95.0 wt.%, or 80.0 wt.% to 99.9 wt.%, or 80.0 wt.% to 99.5 wt.%, or 80.0 wt.% to 99.0 wt.%, or 80.0 wt.% to 95.0 wt.%, based on the total weight of the ceramic composition. The ceramic composition can comprise the mullite remainder component (b) in a range of 30.0 wt.% to 99.9 wt.%, or 40.0 wt.% to 99.9 wt.%, or 50.0 wt.% to 99.5 wt.%, or 60.0 wt.% to 99.0 wt.%, or 70.0 wt.% to 95.0 wt.%, or 80.0 wt.% to 95.0 wt.%, based on the total weight of the ceramic composition.

[0091] The ceramic composition can be processed by standard ceramic processing procedures known to the person skilled in the art. The ceramic composition can be ground to a fine powder by a conventional grinding procedure, for example electric arc grinding, mixed until homogeneity is achieved, and typically melted at a temperature of 2600 °C. The melting can be carried out in an oxidizing atmosphere, for example in air. The resulting molten material can be ground to a particle size in the range of, for example, 100 pm to 250 pm, and the powder can then be formed into the desired shape. Suitable methods of processing the ceramic composition are disclosed, for example, in WO 99 / 01401 Al. The method of forming the ceramic composition can comprise high pressure treatment of the ceramic composition using a press and shaping the shaped body of the ceramic composition from which the object is to be generated. The method of shaping the ceramic composition to form an arbitrary object can further comprise a further temperature treatment, such as a sintering process, and optionally a further pressurization process. Shaping the ceramic composition to form an arbitrary object can comprise standard shaping procedures, such as mechanical treatment, powder processes or ceramic injection molding. Thus, the ceramic composition can be shaped into almost any shape by standard ceramic shaping procedures.

[0092] The combination of applying the coating composition and subsequently curing the applied coating using pulsed infrared radiation by precise application makes it possible to apply a relatively high thickness of the coating in one go.

[0093] The cured coating can have a thickness of 75 pm or more, or 80 pm or more, or 90 pm or more, or 95 pm or more, or 100 pm or more, or 105 pm or more, or 110 pm or more. The thickness of the cured coating can be in the range of 200 pm or less, or 180 pm or less, or 160 pm or less, or 150 pm or less, or 140 pm or less, or 130 pm or less, or 120 pm or less. The thickness of the cured coating can be in the range between any of the above values, such as 75 pm to 200 pm, or 80 pm to 180 pm, or 90 pm to 160 pm, or 95 pm to 150 pm, or 100 pm to 140 pm, or 105 pm to 130 pm, or 110 pm to 120 pm. The thickness can be determined according to DIN EN ISO 2178:2016.

[0094] The substrate to which the protective coating is applied by the above-mentioned method can be, but is not limited to, a vehicle, a storage tank, a windmill, a packaging, a wooden floor and furniture, clothing, electronic products, glass and transparent sheet, sports equipment, a building, a bridge or a part thereof, in particular a vehicle or a part thereof.

[0095] The term "vehicle" is used herein in its broadest sense and includes, but is not limited to, all types of aircraft, spacecraft, water-borne vehicles, and land-borne vehicles. For example, a vehicle can include an aircraft, such as an airplane, including a private airplane, as well as a small, medium, or large commercial passenger jet, cargo plane, and military aircraft; a helicopter, including a private, commercial, and military helicopter; a spacecraft, including a rocket and other spacecraft. A vehicle can include a land-borne vehicle, e.g., a trailer, a car, a truck, a bus, a coach, a van, an ambulance, a fire truck, a motor home, a travel trailer, a go-kart, a horse-drawn carriage, a forklift, a sit-on lawnmower, an agricultural vehicle (e.g., a tractor and a harvester), a construction vehicle (e.g., an excavator, a bulldozer, and a crane), a golf cart, a motorcycle, a bicycle, a train, and a tram. A vehicle can also include a water-borne vehicle, e.g., a ship, a submarine, a boat, a jet ski, and a hovercraft.

[0096] For example, the protective coating can be applied on at least a portion of at least one of the following of a vehicle, such as a land-borne vehicle, such as a car: a body, a chassis, a hood, a fender, a panel, a mirror cover, a trunk threshold trim, a bumper, a front panel, a grille, a running board, a handle, a spoiler, and a side skirt.

[0097] The present disclosure further relates to a coated substrate obtained by the above-mentioned method. Herein, the substrate can be a substrate as defined above.

[0098] Further, the present disclosure relates to the use of a coating composition comprising a film-forming resin and a crosslinker suitable for crosslinking the film-forming resin for forming a protective coating on at least a portion of a substrate by curing the protective coating composition applied to at least a portion of the substrate by applying pulsed infrared radiation having a peak wavelength in the range of 1 pm to 10 pm to the coating with a pulse duration of less than 100 ps.

[0099] Herein, the coating composition can be a coating composition as described above.

[0100] The substrate can be a substrate as defined above.

[0101] The protective coating can be applied to at least a portion of a substrate using the above-mentioned process and apparatus.

[0102] The pulsed infrared radiation can be applied using the above-mentioned process and apparatus.

[0103] The protective coating can be a coating that protects the finish of a vehicle from chipping, scuffing, and stone damage.

[0104] Aspects

[0105] The following clauses summarize some aspects of the present application.

[0106] A first aspect of the present application relates to a method for applying a protective coating to a substrate, the method comprising:

[0107] (i) applying a fluid coating composition on at least a portion of a surface of the substrate by precise application substantially free of overspray, wherein the coating composition comprises a film-forming resin and a crosslinker suitable for crosslinking the film-forming resin; and

[0108] (ii) applying pulsed infrared radiation to the applied coating composition with a peak wavelength in the range of 3 to 10 pm with a pulse duration of less than 100 ps to form a cured coating.

[0109] A second aspect of the present application relates to the method according to the first aspect, wherein the coating composition is a solvent-borne two-component (2K) composition.

[0110] A third aspect of the present application relates to the method according to any of the preceding aspects, wherein the coating composition is a clearcoat composition.

[0111] A fourth aspect of the present application relates to the method according to any of the preceding aspects, wherein the film-forming resin comprises an acrylic polyol resin, a polyester resin, a polyether resin, a polyurethane resin, or a combination thereof, and the crosslinker comprises a polyisocyanate.

[0112] A fifth aspect of the present application relates to the method according to any of the preceding aspects, wherein the coating composition further comprises an ultraviolet light absorber, a hindered amine light stabilizer, a catalyst, a rheology modifier, a sag control agent, a scratch and mar resistance additive, an anti-foam additive, a leveling additive, or any combination thereof.

[0113] A sixth aspect of the present application relates to the method according to any of the preceding aspects, wherein (i) the coating composition is applied to a portion of a substrate having an existing coating on the surface to which the coating composition is applied.

[0114] A seventh aspect of the present application relates to the method according to the sixth aspect, wherein the existing coating is a cured multilayer coating.

[0115] An eighth aspect of the present application relates to the method according to the sixth or seventh aspect, wherein the coating composition is applied as an outermost layer on a cured clearcoat layer.

[0116] A ninth aspect of the present application relates to the method according to any of the preceding aspects, wherein (i) the coating composition is applied on a portion of the surface without masking those portions of the surface not to be coated by the coating composition with a removable material.

[0117] A tenth aspect of the present application relates to the method according to any of the preceding aspects, wherein (i) the coating composition is applied as a continuous jet, as a continuous stream of droplets, and / or as drop-on-demand.

[0118] An eleventh aspect of the present application relates to the method according to any of the preceding aspects, wherein the peak wavelength of the pulsed infrared radiation is in the range of 3 pm to 6 pm or 3 pm to 4 pm.

[0119] A twelfth aspect of the present application relates to the method according to any of the preceding aspects, wherein the pulsed infrared radiation is applied with a pulse duration in the range of 7 ps to 17 ps or 10 ps to 14 ps.

[0120] A thirteenth aspect of the present application relates to the method according to any of the preceding aspects, wherein the pulsed infrared radiation is applied with a pulse frequency in the range of 350 Hz to 450 Hz or 400 Hz to 450 Hz.

[0121] A fourteenth aspect of the present application relates to the method according to any of the preceding aspects, wherein the pulsed infrared radiation is applied with a pulse energy in the range of 250 W / cm 2 to 350 W / cm 2 or 290 W / cm 2 to 320 W / cm 2 .

[0122] A fifteenth aspect of the present application relates to the method according to any of the preceding aspects, wherein the pulsed infrared radiation is provided by an infrared light source comprising a surface comprising a ceramic composition capable of absorbing heat and emitting infrared radiation with a peak wavelength in the range of 3 pm to 10 pm.

[0123] A sixteenth aspect of the present application relates to the method according to any of the preceding aspects, wherein (ii) the coating is cured by applying the pulsed infrared radiation for a total time in the range of 30 seconds to 5 minutes or 1 minute to 3 minutes.

[0124] A seventeenth aspect of the present application relates to the method according to any of the preceding aspects, wherein the thickness of the cured coating obtained in (ii) is in the range of 75 pm to 200 pm, or 80 pm to 180 pm, or 90 pm to 160 pm, or 95 pm to 150 pm, or 100 pm to 140 pm, or 105 pm to 130 pm, or 110 pm to 120 pm.

[0125] An eighteenth aspect of the present application relates to the method according to any of the preceding aspects, wherein the substrate is a vehicle or a part thereof.

[0126] The nineteenth aspect of the present application relates to the method according to the eighteenth aspect, wherein the protective coating is applied on at least a portion of at least one of the following of the vehicle: body, chassis, hood, fender, rocker panel, rearview mirror cover, trunk threshold trim, bumper, front panel, grille, running board, handle, spoiler, and side skirt.

[0127] The twentieth aspect of the present application relates to a coated substrate obtained by the method according to any one of the preceding aspects.

[0128] The twenty-first aspect of the present application relates to the use of a coating composition comprising a film-forming resin and a crosslinker suitable for crosslinking the film-forming resin for forming a protective coating on at least a portion of a substrate by curing the protective coating composition applied to at least a portion of the substrate by applying pulsed infrared radiation having a peak wavelength in the range of 1 to 10 pm to the coating with a pulse duration of less than 100 ps.

[0129] The twenty-second aspect of the present application relates to the use according to the twenty-first aspect, wherein the coating composition is a coating composition as defined in any one of the first to fifth aspects.

[0130] The twenty-third aspect of the present application relates to the use according to the twenty-first or twenty-second aspect, wherein the substrate is a substrate as defined in any one of the sixth, seventh, or eighteenth to twentieth aspects.

[0131] The twenty-fourth aspect of the present application relates to the use according to any one of the twenty-first to twenty-third aspects, wherein the protective coating composition is applied to at least a portion of a substrate as defined in any one of the first, eighth to tenth, or seventeenth aspects.

[0132] The twenty-fifth aspect of the present application relates to the use according to any one of the twenty-first to twenty-fourth aspects, wherein the pulsed infrared radiation is applied as defined in any one of the first or eleventh to sixteenth aspects.

[0133] The twenty-sixth aspect of the present application relates to the use according to any one of the twenty-first to twenty-fifth aspects, wherein the protective coating is a coating that protects the paint finish of a vehicle from chipping, stone chipping, and abrasion.

[0134] Example

[0135] The following examples are intended to illustrate the present disclosure and should not be construed as limiting the present disclosure in any way.

[0136] Component A was prepared by mixing the compounds given in Table 1 below. Then, 114 g of Component A, 57.6 g of HDI (present as a mixture of uretdione, trimer and homopolymer, all under the trade name Desmodur® N 3600, commercially available from Covestro (Germany), as Component B), and 36.8 g of butyl acetate were combined and thoroughly mixed to give a 2K clearcoat composition with a molar ratio of isocyanate to hydroxyl groups of 1.2:1.0 or 1.0:1.0. commercially available from Covestro (Germany), as Component B), and 36.8 g of butyl acetate were combined and thoroughly mixed to give a 2K clearcoat composition with a molar ratio of isocyanate to hydroxyl groups of 1.2:1.0 or 1.0:1.0.

[0137] Table 1: Component A for protective 2K clearcoat compositions

[0138] Component A Amount [g] Polyester resin 1,2 ]]> 45.7 Acrylic polyol resin 3 ]] 24.4 Ultraviolet light absorbers 4 ]]> 1.08 HALS 5 ]] 1.08 Flow control agent 6 ]]> 0.31 Additives having degassing and defoaming properties 7 ]] 0.04 Catalyst 8 ]]> 3.00 Rheology modifier comprising a polyamide wax thickener 16.5 Solvent 9 ]] 17.0 Other 10 ]] 4.84 Total 114

[0139] 1 Hydroxyl number [mg KOH / g, DIN 53240, 2007-11]: 280; acid number [mg KOH / g, ISO 2114]: 85; solids content [%]: 70, Tg [°C, ASTM D3418-03]: 18; viscosity [mPa-s; 23°C, D = 1000 s -1 , DIN EN ISO 3219 / A3]: 4400

[0140] 2 OH % [on solid resin]: 7.7; acid number: 0-8; solids content: 65; Tg: 37; viscosity 6500

[0141] 3 OH %: 4.5; solids content: 60; viscosity 1250

[0142] 4 Tinuvin 928, commercially available from BASF (Germany)

[0143] 5 Tinuvin 123, commercially available from BASF (Germany)

[0144] 6 BYK-322, commercially available from Byk (Germany)

[0145] 7 BYK-390, commercially available from Byk (Germany)

[0146] 8 Dibutyltin dilaurate (1% solution in butyl acetate)

[0147] 9 N-butyl acetate; ethyl 3-ethoxypropionate; n-butanol

[0148] 10 Fumed silica slurry, anti-scratch additive

[0149] To prepare panels for application of the protective 2K coating compositions described above, steel panels coated with PPG electrodeposition coating (commercially available from ACT Panel, Hillsdale, MI, USA) were sprayed by electrostatic rotary bell applicator in a 3-layer coating stack. A first basecoat (commercially available as Shark Grey High Solids B1 from PPG Industries, Inc., Pittsburgh, PA, USA) was applied at a thickness of about 16-20 pm. After a 340 seconds flash, the same procedure was repeated for a second basecoat (Alpine White waterborne basecoat BIPCU300, commercially available from PPG Industries, Inc., Pittsburgh, PA, USA) at a thickness of about 15-18 pm, and after a 335 seconds flash at room temperature, the panels were dehydrated at 74 °C for 6 minutes. Finally, a clearcoat (TKAPO 1100A and TKAPO B package, commercially available from PPG Industries, Inc, Pittsburgh, PA, USA) was applied in a first pass at a thickness of about 15 pm and in a second pass at a thickness of about 35 pm, with a 1 minute flash in between. After a 10 minutes flash, the panels were cured at 140 °C for 30 minutes.

[0150] The panels in horizontal position were then overcoated with the protective 2K coating compositions described above using an EcoPaintJet precision applicator (commercially available from Dϋrr Systems AG, Bietigheim-Bissingen, Germany) with a nozzle plate of type 056 at a spray head speed of 650 mm / s and a flow rate of about 480 mL / min.

[0151] The coated substrates were then cured using a pulsed infrared light source IR.X Infrarot Modul D2, commercially available from SPS Group GmbH, Germany, for a total of 3 min to obtain a cured film thickness of the protective coating of 110-120 pm. The pulsed infrared light source was facing the substrate to which the protective coating composition to be cured was applied at a distance of 20 cm. The settings shown in Table 2 were applied.

[0152] Table 2:

[0153] Peak wavelength 3 μm - 4 μm Pulse duration 12 μs Pulse energy 320 W / cm 2 ]] Curing temperature 100℃-120℃

Claims

1. A method for applying a protective coating to a substrate, the method comprising: (i) applying a fluid coating composition on at least a portion of a surface of the substrate by precise application substantially free of overspray, wherein the coating composition comprises a film-forming resin and a crosslinker suitable for crosslinking the film-forming resin; and (ii) applying pulsed infrared radiation to the applied coating composition with a peak wavelength in the range of 3 pm to 10 pm with a pulse duration of less than 100 ps to form a cured coating.

2. The method of claim 1, wherein the coating composition is a solvent-borne two-component (2K) composition; and / or wherein the coating composition is a clear coating composition.

3. The method of any of the preceding claims, wherein the film-forming resin comprises an acrylic polyol resin, a polyester resin, a polyether resin, a polyurethane resin, or a combination thereof, and the crosslinker comprises a polyisocyanate; and / or wherein the coating composition further comprises an ultraviolet light absorber, a hindered amine light stabilizer, a catalyst, a rheology modifier, a sag control agent, a scratch and mar resistance additive, an antifoam additive, a leveling additive, or any combination thereof.

4. The method of any of the preceding claims, wherein (i) the coating composition is applied to a portion of a substrate having an existing coating on the surface to which the coating composition is applied.

5. The method of claim 4, wherein the existing coating is a cured multilayer coating.

6. The method of claim 4 or 5, wherein the coating composition is applied as an outermost layer on a cured clear coating layer.

7. The method of any of the preceding claims, wherein (i) the coating composition is applied on a portion of the surface without masking those portions of the surface not to be coated with the coating composition with a removable material; and / or wherein (i) the coating composition is applied as a continuous jet, as a continuous stream of droplets, and / or as drop-on-demand.

8. The method of any of the preceding claims, wherein the pulsed infrared radiation has a peak wavelength in the range of 3 pm to 6 pm or 3 pm to 4 pm; and / or wherein the pulsed infrared radiation is applied with a pulse duration in the range of 7 ps to 17 ps or 10 ps to 14 ps; and / or wherein the pulsed infrared radiation is applied at a pulse frequency of 350 Hz to 450 Hz or 400 Hz to 450 Hz; and / or wherein the pulsed infrared radiation is applied at a pulse energy of 250 W / cm 2 to 350 W / cm 2 or 290 W / cm 2 to 320 W / cm 2 .

9. The method of any of the preceding claims, wherein the pulsed infrared radiation is provided by an infrared light source comprising a surface comprising a ceramic composition capable of absorbing heat and emitting infrared radiation with a peak wavelength in the range of 3 pm to 10 pm; and / or wherein (ii) the coating is cured by applying the pulsed infrared radiation for a total time of 30 seconds to 5 minutes or 1 minute to 3 minutes.

10. The method according to any one of the preceding claims, wherein the thickness of the cured coating obtained in (ii) ranges from 75 pm to 200 pm, or from 80 pm to 180 pm, or from 90 pm to 160 pm, or from 95 pm to 150 pm, or from 100 pm to 140 pm, or from 105 pm to 130 pm, or from 110 pm to 120 pm.

11. The method according to any one of the preceding claims, wherein the substrate is a vehicle or a part thereof.

12. The method according to claim 11, wherein the protective coating is applied on at least a portion of at least one of the following of a vehicle: a body, a chassis, a hood, a fender, a rocker panel, a mirror cover, a trunk lid trim, a bumper, a front valance, a grille, a scuff plate, a handle, a spoiler, and a side skirt.

13. A coated substrate obtained by the method according to any one of the preceding claims.

14. Use of a coating composition comprising a film-forming resin and a crosslinker suitable for crosslinking the film-forming resin for forming a protective coating on at least a portion of a substrate by curing the protective coating composition applied to at least a portion of the substrate by applying pulsed infrared radiation having a peak wavelength in the range from 1 pm to 10 pm to the coating with a pulse duration of less than 100 ps.

15. The use according to claim 14, wherein the coating composition is a coating composition as defined in any one of claims 1 to 3; and / or wherein the substrate is a substrate as defined in any one of claims 4, 5, or 11 to 13; and / or wherein the protective coating composition is applied to at least a portion of a substrate as defined in any one of claims 1, 6 to 7, or 10; and / or wherein the pulsed infrared radiation is applied as defined in any one of claims 1 or 8 to 9; and / or wherein the protective coating is a coating that protects the finish of a vehicle from abrasion, chipping damage, and stonechipping.

16. A coated substrate obtained by the use according to claim 14 or 15. ​ ​ ​