EP4680409A1

EP4680409A1 - Protective coating cured by pulsed ir radiation

Info

Publication number: EP4680409A1
Application number: EP24718654.7A
Authority: EP
Inventors: Hannelore KÜNSTLER; Steffi BROMME; Axel Nagel; Maria Elisabeth GEIER
Original assignee: PPG Industries Ohio Inc
Current assignee: PPG Industries Ohio Inc
Priority date: 2023-03-15
Filing date: 2024-03-12
Publication date: 2026-01-21
Also published as: WO2024191977A1; MX2025010713A; CN120916850A; KR20250153291A

Abstract

The present disclosure relates to a method of applying a protective coating to a substrate comprising applying a fluid coating composition over at least a part of a surface of the substrate by precision application substantially without overspray, and applying pulsed infrared radiation to form a cured coating. Further disclosed are substrates coated by said method and the use of a coating composition for forming a protective coating on at least a part of a substrate by curing the applied composition by pulsed infrared radiation. The present disclosure is particularly useful for protecting a vehicle's paint against stone chipping.

Description

PROTECTIVE COATING CURED BY PULSED IR RADIATION

FIELD

BACKGROUND

Stone chips and other small damages resulting from abrasion, e.g., during a car wash, or wear debris are unfortunately commonly found in the cured paint of vehicles in use. These damages deteriorate not only the appearance of the paint, but also allow humidity, e.g., rainwater and ice, to penetrate and affect the metal underneath the paint by corrosion. Depending on the vehicle's design, certain areas may be more susceptible to such mechanical damages and scratches than others.

Colored sprayable rubber-based stone chip protective coatings as well substantially colorless transparent stone chip protective films have been developed to protect the original paint from such environmental influences. However, both only offer a compromise between protecting the original paint and maintaining its appearance. For instance, stone chip protective films may turn yellow over time and often do not match the original paint's gloss which becomes obvious in particular if they are to be applied only to certain parts of the original paint. Moreover, in conventional spraying techniques’ overspray, i.e., the drifting of paint onto unintended areas, is a problem which usually makes it necessary to mask with a removable material those parts of the surface not intended to be coated. Further, if a dry film thickness of 75 pm or more is desired, sprayable products often have to be applied in several passes with an intermediate drying step until the desired layer thickness is reached.

It would be desirable to provide a solution to these problems. In particular, it would be desirable to have a method for applying a protective coating to a substrate, e.g., a vehicle having an existing multilayer paint, which can be applied in one pass to give 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 and without the need for masking those parts of the substrate's surface to which the coating shall not be applied.

This object has been solved by the subject-matter defined in the appended claims and described herein.

SUMMARY

The present disclosure relates to a method for applying a protective coating to a substrate, the method comprising: (i) applying a fluid coating composition over at least a part of a surface of the substrate by precision application substantially without overspray, wherein the coating composition comprises a film-forming resin and a crosslinking agent suitable for crosslinking the film-forming resin; and (ii) applying pulsed infrared radiation having a peak wavelength in the range of from 3 pm to 10 pm at a pulse duration of less than 100 ps to the applied coating composition to form a cured coating.

The present disclosure further relates to a coated substrate obtained by said method.

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

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

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 variation found in their respective testing measurements.

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

In the present disclosure, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and/or” unless specifically stated otherwise, even though “and/or” may be explicitly used in certain instances. Further, in this application, the use of “a” or “an” means “at least one” unless specifically stated otherwise. For example, “a” polymer, “a” crosslinker, and the like refer to one or more of any of these items. As used herein, the transitional term “comprising” (and other comparable terms, e.g., “containing” and “including”) is “open-ended” and open to the inclusion of unspecified matter. Although described in terms of “comprising”, the terms “consisting essentially of’ and “consisting of’ are also within the scope of the disclosure.

As used herein, the term “including” 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", "overlay" and "provided on/over" mean formed, overlay, deposited, or provided on but not necessarily in contact with the surface. For example, a coating layer "formed over" a substrate does not preclude the presence of one or more other coating layers of the same or different composition located between the formed coating layer and the substrate.

The present disclosure relates to a method for applying a protective coating to a substrate. The method comprises: (i) applying a fluid coating composition over at least a part of a surface of the substrate by precision application substantially without overspray; and (ii) applying pulsed infrared radiation having a peak wavelength in the range of from 3 pm to 10 pm at a pulse duration of less than 100 ps to the applied coating composition to form a cured coating. The coating composition comprises a film-forming resin and a crosslinking agent suitable for crosslinking the film-forming resin.

As used herein, the term "protective coating" refers to a coating making the surface of an object which is coated with said coating more resistant to an external impact in comparison to the surface of the same object not being coated with said protective coating. The surface to which the protective coating is applied may be at least a part of the bare substrate's surface, but may also be an existing single or multilayer-coating on at least a part of an object's surface. The external impact may comprise thermal, radiant, chemical, electric, or mechanical impact, or a combination thereof. The method of the present disclosure may be particularly useful for protecting a vehicle's paint or a part thereof against abrasion, wear debris and stone chipping. As used herein, the term "fluid" refers a material that continuously deforms (flows) under an applied shear stress, in particular a liquid, i.e., a non-gaseous fluid, including non-Newtonian fluids. The coating composition may be a liquid at room temperature (23 °C) and atmospheric pressure (101 .3 kPa).

As used herein, the term “precision application substantially without overspray" refers to an application of the coating composition with the help of a device in such a way that drift of spray mist to unintended locations, including non-targeted areas on the substrate being coated and non-substrate areas, is avoided. Herein, at least 85%, or at least 95%, or at least 98%, or at least 99%, or 100% by weight (wt.%) of the applied coating composition is deposited on the targeted area on the substrate's surface, although there is no direct contact between the surface of the substrate to be coated and the device used for applying the coating composition as it would be the case when applying the coating composition by brushing, rolling or the like.

Non-limiting examples of devices that can apply coating compositions substantially without overspray include devices that apply compositions as a continuous jet, as continuous stream of droplets, and/or as a drop on-demand. Specific non-limiting examples of such devices include continuous inkjet printers, gas-ejection droplet generators, vibrating tip droplet generators, piezo-actuated micro-pneumatic droplet generators, and electrohydrodynamic droplet generators.

A particular non-limiting example of such a device comprises one or more nozzle applicators which, similar to an inkjet printhead and unlike conventional paint atomizers, use a plurality of nozzles of small diameter, e.g., of 0.1 mm, to direct parallel streams, jets or droplets of the coating composition onto the substrate's surface. Herein, the individual nozzles may selectively be controlled and actuated with the aid of a control unit or device. The nozzle applicator may 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, with the aid of a multiaxis robot controlled and actuated by the control unit or device. The plurality of nozzles may, for instance, be arranged next to one another in one or more rows, forming a nozzle plate or printhead. Such devices are described, for instance, in European patent application EP 3 532 206 A1 and are commercially available under the tradename EcoPaintJet from Durr Systems AG (Bietigheim-Bissingen, Germany) or PixelPaint from ABB Asea Brown Boveri Ltd (Zurich Switzerland).

As used herein, the term “nozzle” refers to a component of an applicator having an opening through which a coating composition flows, is ejected or jetted. Unless otherwise indicated, the term “nozzle” is used interchangeably with any of a valve jet, or piezo-electric, thermal, acoustic, or ultrasonic actuated valve jet or nozzle.

As used herein, the term “film-forming resin” refers to a resin that may form a self- supporting continuous film on at least a horizontal surface of a substrate upon removal of any diluents or carriers present in the composition or upon curing at ambient conditions, e.g., at a temperature in the range of 20 to 25 °C, or at elevated temperatures, e.g., at a temperature in the range of 40 to 200 °C. The terms “resin” and “resinous” and the like are used interchangeably with the terms “polymer” and “polymeric” and the like, and include homo- and copolymers as well as prepolymers and oligomers, unless indicated otherwise. Further, the term "polymer" is used herein in its common meaning in the art, referring to macromolecular compounds, i.e. , compounds having a relatively high molecular weight (e.g., 500 Da or more), the structure of which comprises multiple repetition units (also referred to as “mers”) derived, actually or conceptually, from chemical species of relatively lower molecular mass. Unless indicated otherwise, molecular weights are on a weight average basis (“M_w”) and are determined by gel permeation chromatography using polystyrene standards.

By ambient conditions is meant that the composition is cured without the aid of heat, for example, without baking in an oven, use of forced air, or the like.

The film-forming resin may comprise at least one of an acrylic resin, a vinylic resin, a polyester resin, a polyether resin, a polysiloxane resin, an epoxy resin, a polyurethane resin, a polyamide resin, a copolymer thereof, or a mixture thereof. The film-forming resin may comprise an acrylic resin, such as an acrylic polyol resin.

Suitable acrylic resins may be obtained by polymerizing one or more monomers comprising substituted or unsubstituted (meth)acrylic acids and (meth)acrylates. Herein, the terms “(meth)acrylic acid” and “(meth)acrylate” and similar terms refer both to the acrylic acid or acrylate and the corresponding methacrylic acid or methacrylate, 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 functional groups-containing (meth)acrylates. As used herein, the term “functional group” refers to a group that includes one or a plurality of atoms other than hydrogen and sp³ carbon atoms. Examples of functional groups include, but are not limited to, hydroxyl, carboxylic acid, amido, isocyanate, urethane, thiol, amino, sulfone, sulfoxide, phosphine, phosphite, phosphate, halide, epoxy, and the like. Non-limiting examples of acrylic resins may include acrylic resins derived from methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, iso-butyl (meth)acrylate, 2-ethyl hexyl (meth)acrylate, iso-octyl (meth)acrylate, isobornyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 3,3,5-trimethyl-cyclohexyl (meth)acrylate, 3-methylphenyl (meth)acrylate, 1 -naphtyl (meth)acrylate, 3-phenyl-n-propyl (meth)acrylate, 2-phenyl-aminoethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycidyl (meth)acrylate or combinations thereof.

The acrylic resin may have a hydroxyl value in a range of from 20 to 400 mg KOH/g, such as from 30 to 350 mg KOH/g, such as from 40 to 300 mg KOH/g, such as from 50 to 250 mg KOH/g, and may represent an acrylic polyol. The hydroxyl value may be determined according to DIN EN ISO 4629-1 :2016. Nonlimiting 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, 9-hydroxynonyl (meth)acrylate, acrylic polyols derived from glycidyl (meth)acrylate-acid adducts or acrylic acid adducts of the glycidyl ester of neodecanoic acid commercially available under the tradename Cardura™ E10 from Hexion Inc. (Columbus, USA), or combinations thereof. Suitable acrylic resins include, but are not limited to, acrylic resins, in particular acrylic polyols, commercially available under the trademark SETALUX®, including, but not limited to, SETALUX® 1776 VS-65, SETALUX® 1774 SS-70, SETALUX® 1797 SS-70, SETALUX® 1762 W-70, SETALUX® 1760 VB-64, SETALUX® 1795 VX-74, SETALUX® 91767 VX-60, SETALUX® D A 870 BA, from Allnex Germany GmbH (Germany) and acrylic resins commercially available under the trademark VIACRYL®, such as VIACRYL SC 370/75SNA, from Allnex Germany GmbH (Germany).

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

Suitable polyester resins may be obtained by condensation of a polyol and a polyacid or by ring-opening polymerization of lactones. As used herein, the term “polyol” refers to a compound having more than one hydroxyl group per molecule, e.g., 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, e.g., 2, 3, 4, 5, 6 or more carboxylic acid groups per molecule, and includes anhydrides of the corresponding acid. Suitable polyols include, but are not limited to, alkylene glycols, such as ethylene glycol, propylene glycol, butylene glycol, 1 ,6-hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, polyethylene glycol having a molecular weight in the range of 200 to 10.000 g/mol, polypropylene glycol having a molecular weight in the range of 200 to 10.000 g/mol, polybutylene glycol having a molecular weight in the range of 300 to 10.000 g/mol and neopentyl glycol; bisphenol A; hydrogenated bisphenol A; bisphenol F; hydrogenated bisphenol F; cyclohexanediol; propanediols such as

1 .2-propanediol, 1 ,3-propanediol, butyl ethyl propanediol, 2-methyl-1 ,3- propanediol and 2-ethyl-2-butyl-1 ,3-propanediol; butanediols such as 1 ,4- butanediol, 1 ,3-butanediol, 2,3-butanediols, 1 ,2-butanediols, 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 to 10.000 g/mol; polyether glycols, such as poly(oxytetramethylene) glycol; trimethylolpropane; pentaerythritol; dipentaerythritol; trimethylolethane; trimethylolbutane; dimethylolcyclohexane and glycerol. Suitable polyacids may include, but are to limited to, maleic acid; fumaric acid; itaconic acid; adipic acid; azelaic acid; succinic acid; sebacic acid; glutaric acid; phthalic acid; isophthalic acid; 5-tert-butylisophthalic acid; tetrachlorophthalic acid; trimellitic acid; naphthalene dicarboxylic acid; naphthalene tetracarboxylic acid; terephthalic acid, hexahydrophthalic acid; methyl hexahydrophthalic acid; dimethyl terephthalic acid; cyclohexane dicarboxylic acid, 1 ,3-cyclohexane dicarboxylic acid; 1 ,4-cyclohexane dicarboxylic acid; tricyclodecanepolycarboxylic acid, endomethylenetetrahydrophthalic acid; endoethylenehexahydrophthalic acid; cyclohexane tertracarboxylic acid; cyclobutanetetracarboxylic acid and anhydrides of all the aforementioned polyacids. Suitable lactones may include, but are not limited to, p-propiolactone; y-butyrolactone; S-valerolactone; e-caprolactone; a-angelica lactone; and mixture thereof. Suitable polyester resins include, but are not limited to, polyester resins commercially available under the trademark SETAL®, such as SETAL® 1715 VX-74, SETAL® 91703 SS-53, and SETAL® 91715 SS-55 from Allnex Germany GmbH (Germany), and Uralac™, such as Uralac™ SC-960 E-75, Uralac™ SY-942 F-65, and Uralac™ SY-943 E-75 from DSM NeoResins (The Netherlands).

Suitable polyether resins may include, but are not limited to, polyalkylene ether polyols, such as poly(tetramethylene ether) glycol, polyethylene glycol, polypropylene glycol, and copolymers thereof. The polyether resins may be prepared by oxyalkylation of 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 may be the polyols described above for producing the polyester resins. In particular, suitable polyols may include, but are not limited to, bisphenol A, trimethylol propane, pentaerythritol, glycerol, sorbitol, alkylene glycols, such as ethylene glycol, propylene glycol, butylene glycol, 1 ,6-hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol and tripropylene glycol, and combinations thereof. Poly(tetramethylene ether) glycol may be prepared by the polymerization of tetrahydrofuran in the presence of Lewis acid catalysts such as boron trifluoride, tin(IV) chloride, antimony pentachloride, antimony trichloride, phosphorus pentafluoride, or sulfonyl chloride. Suitable polyether resins include, but are not limited to, polyether resins commercially available under the trademark Arcol®, such as Arcol® 1150 from Covestro (Germany), Desmophen®, such as Desmophen® 1920, and Desmophen® 550 from Covestro (Germany), and Polymeg®, such as Polymeg® 1000 from Lyondellbasell (Netherlands).

Suitable polysiloxane resins may include, but are not limited to, alkyl substituted polysiloxanes, aryl polysiloxanes, copolymers, blends and mixtures thereof. The alkyl substitution may be selected from short chain alkyl groups of 1 to 4 carbon atoms, such as methyl or propyl. The aryl substitution may comprise phenyl groups. Suitable polysiloxane resins include, but are not limited to, Silres® 601 or Silres® M 50 E, both commercially available from Wacker Chemie AG (Germany), and DOWSIL™ RSN-6018, commercially available from Dow Chemical Company (USA).

Suitable epoxy resins may be prepared by reacting a compound comprising at least one epoxide functionality and a cyclic co-reactant comprising at least two hydroxyl groups. Examples of suitable compounds comprising one epoxide functionality include, but are not limited to, glycidol; epichlorohydrin; glycidol amines and mixtures thereof. As used herein, the terms “epoxy” and “epoxide” are used interchangeably. Examples of suitable cyclic co-reactants comprising at least two hydroxy groups include, but are not limited to, bisphenol A; hydrated bisphenol A; bisphenol F; hydrated bisphenol F; novolac resins such as phenolic 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, commercially available from Hexion (USA); Epodil 757, commercially available from Evonik Corporation (Germany); Araldite GY 2600, Araldite GY 281 and Araldite EPN 1 138, commercially available from Huntsman (USA).

Suitable polyurethane resins may 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, e.g., 2, 3, 4, 5, 6, or more isocyanate groups per molecule. Suitable polyisocyanates include aliphatic polyisocyanates, such as 2,2,4-trimethyl hexamethylene diisocyanate, 2,4,4- trimethyl hexamethylene 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, tetramethyl xylylene diisocyanate and polymethylene polyphenyl isocyanate. Nonlimiting examples of suitable polyols may be the polyols described above for producing the polyester resins. The polyurethane resins may be prepared by reacting a polyisocyanate and a polyol, such as those mentioned above, such that the OH/NCO equivalent ratio is greater than 1 :1 so that free hydroxyl groups are present in the polyurethane resins or such that the OH/NCO equivalent ratio is less than 1 :1 so that free isocyanate groups are present in the polyurethane resins. In particular, the polyurethane resins may be prepared by reacting a polyisocyanate and a polyol, such as those mentioned above, such that the OH/NCO equivalent ratio is greater than 1 :1 so that free hydroxyl groups are present in the polyurethane resins. The polyurethane resins may include a hydroxyl group or an isocyanate group, in particular a hydroxyl group. Suitable polyurethane resins include, but are not limited to, the reaction product of Desmodur® N 3300 (commercially available from Covestro (Germany)) with an alkylene glycol, such as ethylene glycol or propylene glycol.

Suitable polyamide resins may be prepared by polymerizing a polyamine and a polyacid or by ring-opening polymerization of lactams. Herein, the term “polyamine” refers to a compound having more than one amine group per molecule, e.g., 2, 3, 4, 5, 6, or more amine groups per molecule. Suitable polyamines include, but are not limited to, aliphatic diamines such as

1 .2-ethanediamine, 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; cycloaliphatic diamines such as 2,4'-diamino dicyclohexylmethane, 4,4'-diamino dicyclohexylmethane, 3,3'-dimethyl-4,4'- diamino dicyclohexylmethane and 3,3'-diethyl-4,4'-diaminodicyclohexylmethane; and aromatic diamines such as 1 ,2-benzenediamine, 1 ,3-benzenediamine,

1 .4-benzenediamine, 1 ,5-naphthalenediamine, 1 ,8-naphthalenediamine,

2.4-toluenediamine, 2,5-toluenediamine, 2,6-toluenediamine, and 3,3'-dimethyl- 4,4'-biphenyldiamine. Non-limiting examples of suitable polyacids may include those listed above for preparing polyesters. Suitable lactams may include, but are not limited to, [3-propiolactam; y-butyrolactam; S-valerolactam; e-caprolactam; and mixture thereof. Suitable polyamide resins include, but are not limited to, polyamide resins commercially available under the trademark Flex-Rez™, such as Flex-Rez™ 0080CS, Flex-Rez™ 1060CS, Flex-Rez™ 1074 CS A, from Lawter (USA).

The film-forming resin may 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 may 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 may be present in the coating composition in the range between any of the above-mentioned values, such as from 25 to 95 wt.%, such as from 25 to 90 wt.%, such as from 25 to 85 wt.%, such as from 25 to 80 wt.%, such as from 30 to 95 wt.%, such as 30 to 90 wt.%, such as 30 to 85 wt.%, such as 30 to 80 wt.%, such as 40 to 95 wt.%, such as 40 to 90 wt.%, such as 40 to 85 wt.%, such as 40 to 80 wt.%, such as 50 to 95 wt.%, such as 50 to 90 wt.%, such as 50 to 85 wt.%, such as 50 to 80 wt.%, based on the total weight of solids in the coating composition.

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).

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 of the constituent polymer molecules. The terms "crosslinking agent", "curing agent" and "crosslinker" are herein used interchangeably. Curing or crosslinking reactions may be induced, for example, by exposing the coating composition to heat or radiation, but may also be carried out at ambient conditions to form a cured coating. The crosslinking agent may comprise at least one of a polyepoxide, a polyisocyanate and an amino resin.

Suitable polyepoxides may include, but are not limited to, low molecular weight polyepoxides, e.g., polyepoxides having a molecular weight in the range of from 200 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 to 10.000 g/mol. Suitable low molecular weight polyepoxides include, but are not limited to, 3,4-epoxycyclohexylmethyl, 3,4-epoxycyclohexanecarboxylate 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 may include, but are not limited to, polyglycidyl ethers of cyclic polyols, for example, polyglycidyl ethers of polyhydric phenols such as bisphenol A, bisphenol F, resorcinol, hydroquinone, benzenedimethanol, phloroglucinol, and catechol; or polyglycidyl ethers of polyhydric alcohols such as aliphatic polyols, particularly cycloaliphatic polyols such as 1 ,2-cyclohexane diol, 1 ,4-cyclohexane diol, 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-tertiarybutylcyclohexyl)propane, 1 ,3- bis(hydroxymethyl)cyclohexane and 1 ,2-bis(hydroxymethyl)cyclohexane. Examples of aliphatic polyols may include, but are not limited to inter alia, trimethylpentanediol and neopentyl glycol. Suitable polyepoxides include, but are not limited to, EPONEX™ 1510, Epon® 828, EPIKOTE™ Resin 828, commercially available from Hexion Inc. (USA).

Suitable polyisocyanates may be aliphatic, aromatic, or a mixture thereof. As used herein, the term "polyisocyanate" refers to a compound having at least two isocyanate groups per molecule, and includes monomeric polyisocyanates, such as, monomeric diisocyanates, as well as dimers (uretdiones), trimers (isocyanurates), oligomers (e.g., being formed from up to 15 monomeric polyisocyanates), allophanate, 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 an isocyanate with a blocking agent, whereby the adduct is thermally instable and dissociates (unblocks) at elevated temperatures, such as temperatures above 120 °C. The term “unblocked isocyanate” refers to a polyisocyanate without blocking agents. The polyisocyanate may be prepared from a variety of isocyanate-containing materials. Examples of suitable polyisocyanates include trimers prepared from, but not limited to, toluene diisocyanate, 4,4'-methylene-bis(cyclohexyl isocyanate), isophorone diisocyanate, an isomeric mixture of 2,2,4- and 2,4,4-trimethyl hexamethylene diisocyanate, 1 ,6-hexamethylene diisocyanate, tetramethyl xylylene diisocyanate and 4,4'-diphenylmethylene diisocyanate. Isocyanate groups of the polyisocyanates may be blocked or unblocked as desired. Examples of suitable blocking agents include those materials which would unblock at elevated temperatures, e.g., at temperatures above 120 °C, such as lower aliphatic alcohols having 1 to 6 carbon atoms including methanol, ethanol, and n- butanol; cycloaliphatic alcohols such as cyclohexanol; aromatic alkyl alcohols such as phenyl carbinol and methylphenyl carbinol; and phenolic compounds such as phenol itself and substituted phenols wherein the substituents do not affect coating operations, such as cresol and nitrophenol. Glycol ethers may 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 epsilon-caprolactam, pyrazoles such as dimethyl pyrazole, and amines such as dibutyl amine. Suitable polyisocyanates include, but are not limited to, polyisocyanates, commercially available under the trademark Desmodur®, such as 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) as well as mixtures thereof.

Suitable amino resins may be obtained from the condensation reaction of an aldehyde, such as formaldehyde, with a compound comprising 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 comprising at least two amine or amide groups include, but are not limited to, melamine, urea and benzoguanamine. Suitably, the amino resins may be etherified, typically, with an alcohol, such as methanol, ethanol, butanol or mixtures thereof. Suitable amino resins include, but are not limited to, Maprenal® Amino Resin, such as Maprenal® MF 612/70B, Maprenal® MF 613/71 B and Maprenal® MF 650/55IB commercially available from Prefere Resin Holding GmbH (Germany), Cymel® Amino Crosslinkers, such as Cymel® 303, Cymel® 202, Cymel® 1161 , Cymel® 325 and Cymel® 1 133 commercially available from Allnex Industries (Germany); Setamine® aminoresins, such as Setamine® US-138 BB-70, and Setamine® US-146 BB-72 commercially available from Allnex (Germany).

The crosslinking agent may 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 crosslinking agent may be present in an amount of no more than 75 wt.%, such as no more than 70 wt. %, such as no more than 60 wt.%, such as no more than 50 wt.%, based on the total weight of solids in the coating composition. The crosslinking agent may be present in the coating composition in range between any of the above-mentioned values, such as from 5 to 75 wt.%, such as from 5 to 70 wt.%, such as from 5 to 60 wt.%, such as from 5 to 50 wt.%, such as from 10 to 75 wt. %, such as 10 to 70 wt.%, such as 10 to 60 wt.%, such as 10 to 50 wt.%, such as 15 to 75 wt.%, such as 15 to 70 wt.%, such as 15 to 60 wt.%, such as 15 to 50 wt.%, such as 20 to 75 wt.%, such as 20 to 70 wt.%, such as 20 to 60 wt.%, such as 20 to 50 wt.%, based on the total weight of solids in the coating composition.

The coating composition may further comprise a solvent or a mixture of solvents. Suitable solvents include organic solvents and mixtures thereof. The organic solvent may comprise any suitable organic solvents known in the art. Non-limiting examples of suitable organic solvents may include, but are not limited to, alcohols, glycol ethers, esters, ether esters and ketones, aliphatic and/or aromatic hydrocarbons, and mixtures thereof, such as, for example, methanol, ethanol, isopropanol, n-butanol, 2-butanol, tridecyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, 3-butoxy-2-propanol, ethyl 3-ethoxypropionate, butyl glycol, butyl glycol acetate, butanol, dipropylene glycol methyl ether, diethylene glycol monobutyl ether, butyl glycolate, hexane, heptane, octane, toluene, xylene, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, 2- butoxyethyl acetate, amyl acetate, isoamyl acetate, n-butyl acetate, diethylene glycol butyl ether acetate, acetone, xylene, toluene, solvent naphtha, and mixtures thereof. The solvent may 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 may 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 may be present in the coating composition in range between any of the above-mentioned values, such as from 5 to 70 wt.%, such as from 5 to 65 wt.%, such as from 5 to 60 wt.%, such as from 5 to 55 wt.%, such as from 5 to 50 wt.%, such as from 10 to 70 wt.%, such as from 10 to 65 wt.%, such as from 10 to 60 wt.%, such as from 10 to 55 wt.%, such as from 10 to 50 wt.%, such as from 15 to 70 wt.%, such as from 15 to 65 wt.%, such as from 15 to 60 wt.%, such as from 15 to 55 wt.%, such as from 15 to 50 wt.%, such as from 20 to 70 wt.%, such as from 20 to 65 wt.%, such as from 20 to 60 wt.%, such as from 20 to 55 wt.%, such as from 20 to 50 wt.%, such as from 30 to 70 wt.%, such as from 30 to 65 wt.%, such as from 30 to 60 wt.%, such as from 30 to 55 wt.%, such as from 30 to 50 wt.%, based on the total weight of the coating composition.

The coating composition may be a solvent-borne coating composition. As used herein, the term “solvent-borne coating composition” refers to a coating composition which is liquid at room temperature (23 °C) and atmospheric pressure (101 .3 kPa) and comprises one or more organic solvent(s) as the main component of the liquid carrier and less than 50 wt.% of water, such as less than 40 wt.% of water, such as less than 30 wt.% of water, such as less than 20 wt. % of water, such as less than 10 wt.% of water, such as less than 5 wt.% of water, such as less than 2 wt.% of water, such as less than 1 wt.% of water, based on the total weight of the liquid carrier, i.e., the combination of organic solvent(s) and water (if present). The solvent-borne coating composition may be essentially free of water, i.e., the solvent-borne coating composition may comprise less than 0.5 wt.% of water, such as less than 0.2 wt.% of water, such as less than 0.1 wt.% of water, based on the total weight of the liquid carrier. The solvent-borne coating composition may be completely free of water, i.e., the solvent-borne coating composition may comprise 0 wt.% of water based on the total weight of the liquid carrier.

The coating composition may be a multi component coating composition, such as a two component (2K) coating composition. As used herein, the terms "multi component", "multi K" and " multipack" refer to a coating composition that includes a first component which may comprise the film-forming resin, a second component which may comprise the crosslinking agent, and optionally additional components which may or may not comprise film-forming resins or crosslinking agents, respectively, where the components are kept separately until just prior to use. When the multi component coating composition does not include additional components, it is a two component (2K) coating composition.

The coating composition may be a clearcoat composition. As used herein, the term “clearcoat composition” refers to a coating composition which, after drying and/or curing, provides a coating layer that is at least substantially transparent or fully transparent and may 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” refers to a coating, wherein a surface beyond the coating layer is at least partially visible to the naked eye when viewed through the coating. The term “fully transparent” refers to a coating, wherein a surface beyond the coating layer is completely visible to the naked eye when viewed through the coating. The clearcoat may be substantially free of a pigment. Substantially free of a pigment may refer to a “tinted clearcoat”, which may be a coating composition that includes less than 3 wt.% of pigment, based on the total solids, such as less than 2 wt.%, less than 1 wt.%, or 0 wt.%.

As used herein, the term “pigment” refers to 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. Alternatively, the coating composition may comprise 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, salt type (lakes) pigments, benzimidazolone pigments, metal complex pigments, isoindolinone pigments, isoindoline pigments, polycyclic phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, diketopyrrolo pyrrole pigments, thioindigo pigments, anthraquinone pigments, indanthrone pigments, anthrapyrimidine pigments, flavanthrone pigments, pyranthrone pigments, anthanthrone pigments, dioxazine pigments, triarylcarbonium pigments, quinophthalone pigments, diketo pyrrolo pyrrole red (“DPPBO red”), titanium dioxide, carbon black and mixtures thereof. Suitable dyes include, but are not limited to, acid dyes, azoic 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 triphenyl methane. .

The film-forming resin present in the coating composition may comprise 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 may be selected from any of those described above.

The crosslinking agent present in the coating composition may comprise a polyisocyanate. Suitable polyisocyanates may be selected from any of those described above.

The coating composition may further comprise an UV light absorber, a hindered amine light stabilizer, a catalyst, a rheology modifier, a sag control agent, a scratch- and mar-resistance additive, a defoaming additive, a leveling additive, or any combinations thereof. As used herein, the term “UV light absorber” refer to a compound used to absorb UV radiation, e.g., in order to reduce the UV degradation of a polymeric material in comparison to that of the same polymeric material not comprising said compound. Examples of suitable UV light absorbers include, but are not limited to CYASORB light stabilizers, such as CYASORB UV-1164L available from Solvay (Netherlands) and TINUVIN® 1130 available from BASF (Germany).

As used herein, the term “hindered amine light stabilizer” refers to a compound comprising an amine functional group which is added to polymeric materials to inhibit or retard their degradation by, e.g., photo-oxidation, in comparison to that of the same composition not comprising said compound. Typically, derivatives of tetramethylpiperidine are used. Examples of suitable hindered amine light stabilizers include, but are not limited to, Tinuvin® light stabilizers, such as TINUVIN® 292, TINUVIN® 123, TINUVIN® 328, TINUVIN® 622, TINUVIN® 783, and TINUVIN® 770 available from BASF (Germany).

As used herein, the term “catalyst" refers to a catalyst facilitating any desired curing reaction. Any catalyst typically used to catalyze crosslinking reactions may be used, and there are no particular limitations on the catalyst. Non-limiting examples of catalysts include, but are not limited to, phenyl acid phosphate, sulfonic acid functional catalysts, such as dodecylbenzene sulfonic acid (DDBSA), dinonyl naphthalene sulfonic acid, dinonyl naphthalene disulfonic acid, salts of the aforementioned sulfonic acids, complexes of organometallic compounds including tin, zinc, zirconium, strontium or bismuth, such as stannous octoate, butyl stannoic acid, dibutyltin dilaurate (DBTL), dibutyltin diacetate, dibutyltin mercaptide, dibutyltin diacetate, dibutyltin dimaleate, dimethyltin diacetate, dimethyltin dilaurate, 1 ,4-diazabicyclo[2.2.2]octane, bismuth carboxylates, and the like, tertiary amines, such as 1 ,8-diazabicyclo[5.4.0]undec-7-en, triethyl amine, and the like, or any combinations of the foregoing catalysts.

Alternatively, the coating compositions may be essentially free of a catalyst. As used throughout this specification, unless stated otherwise, the term “essentially free” relates to compositions comprising the respective compound in an amount of less than 0.5 wt.%, such as 0.2 wt.% such as 0.1 wt.%, based on the total weight of the coating composition. The coating compositions may be completely free of catalyst, i.e. , the coating compositions may comprise 0 wt.% of catalyst.

As used herein, a “rheology modifier” refers to a component that adjusts flow behavior of a composition by increasing the viscosity of the composition it is in contact with compared to the same composition which is 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 clays, such as bentone, a hydrophobically modified ethylene-oxide polymer, a rubber latex such as for example styrenebutadiene rubber particles dispersed in an aqueous liquid medium, cellulose derivatives, polyamide waxes, microgels, solvent borne polymer-based associative thickener, exemplified by RHEOBYK-410, RHEOBYK 415; RHEOBYK 430, and RHEOBYK 431 , commercially available from BYK-Chemie GmbH (Germany), EFKA® RM 1463, commercially available from BASF SE (Germany), and Crayvallac®, commercially available from Biesterfeld AG (Germany), or any combination thereof.

As used herein, the term “sag control agent” refers to a compound which minimizes sagging, i.e., defects such as tear drops caused by gravity-driven flow of wet coating compositions when applied to a substrate, in particular a substrate comprising a non-horizontal, e.g., a vertical surface, in comparison that of the same wet coating composition not comprising a sag control agent. Suitable flow control agents, especially sag control agents, may include, but are not limited to, the compounds described in US 4,31 1 ,622 A, EP 0 192 304 A1 and EP 3 728 482 A1.

As used herein, the term “scratch- and mar-resistance additive" refers to a compound reducing degradation of a film formed from a coating composition after a mechanical impact on the film in comparison to degradation of a film formed from the same coating composition not comprising said compound. For instance, the scratch- and mar-resistance additive may aid in creating a sacrificial layer, reduce the surface tension of the film, introduce a material that protrudes above the film surface, or a combination thereof. Suitable scratch- and mar-resistance additives include, but are not limited to, waxes, including natural, synthetic, mineral hydrocarbon and petroleum waxes, silicone-based agents, fluoro- and polytetrafluoroethylene-based agents, silica, including colloidal silica, and metal oxides, including alumina. Examples of scratch- and mar-resistance additives include NANOBYK-3650 and NANOBYK-3652, commercially available from BYK- Chemie GmbH (Germany).

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

As used herein, the term "levelling agent" refers to a compound enhancing the thickness uniformity of the cured coating in comparison to a coating to that of a coating formed from the same composition not comprising said agent. Suitable levelling agents that may be used include, but are not limited to, BYK-320 or BYK- 306 commercially available from BYK-Chemie GmbH (Germany).

The substrate over which the protective coating composition can be applied includes a wide range of substrates. For example, the protective coating composition can be applied to a vehicle substrate, an industrial substrate, an aerospace substrate, and the like.

As a nonlimiting example, the substrate can include a polymer or a composite material such as a fiberglass composite. Vehicle parts 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 nonlimiting examples, the substrate can be part of bumpers, spoilers, wheel covers, door handles, plastic cladded doors, water craft, motorcycles, hoods, body panels, and architectural cladding such as signage or logos for buildings. Nonlimiting 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. The 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.

Nonlimiting 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 suitable when pretreated with an appropriate solution known in the art, such as a metal phosphate solution, an aqueous solution containing a Group II I B or IVB metal, an organophosphate solution, an organophosphonate solution, and combinations thereof, as discussed below. Nonlimiting examples of aluminum alloys include those alloys used in the automotive or aerospace industry, such as 2000, 6000, or 7000 series aluminums; 2024, 7075, 6061 are particular examples. Alloys can be unclad or they can contain a clad layer on a surface, the clad layer consisting of a different aluminum alloy than the base/bulk alloy beneath the clad layer.

Nonlimiting examples of substrates include more than one metal or metal alloy in that the substrate can be a combination of two or more metal substrates assembled together such as hot-dipped galvanized steel assembled with aluminum substrates.

Nonlimiting examples of the shape of the metal substrate include in the form of a sheet, plate, bar, rod or any shape desired, but it in many cases it can be in the form of an automobile part, such as a body, door, trunk lid, fender, hood or bumper. The thickness of the substrate can vary as desired.

Non-metallic substrates include, but are not limited to polymeric substrates, such as polyester, polyolefin, polyamide, cellulosic, polystyrene, polyacrylic, polyethylene naphthalate), polymethacrylate, polypropylene, polyethylene, nylon, ethylene vinyl alcohol (EVOH), polylactic acid (PLA), other “green” polymeric substrates, polyethylene terephthalate) (PET), polycarbonate, polycarbonate acrylobutadiene styrene (PC/ABS), polyamide, and/or plastic composite: substrates such as: glass or carbon fiber composites. The non-metallic substrates can include wood, veneer, wood composite, particle board, medium density fiberboard, cement, stone, glass, paper, cardboard, textiles leather both synthetic and natural, and the like. The protective coating composition can be applied directly to plastics, flame treated plastic surfaces, plastic with adhesion promoters applied thereon and/or primed plastics.

The coating composition described above may be applied over a part of a substrate, such as those described above, which has an existing coating on the surface over which the above-described coating composition is then applied by the method described herein. The existing coating may be an already cured single- or multi-layer coating, such as, but not limited to, a cured multi-layer coating comprising a primer coat, a basecoat, and a topcoat, e.g., a clearcoat. The layers may be formed from coating compositions known in the art and may be applied and cured by various methods known in the art. As nonlimiting examples, the coatings used for forming these layers of the already existing cured coating may be aqueous or solvent based coatings, powder coatings and/or electro coatings known in the art. These coatings may be applied using, e.g., conventional, brush, roller, spray, powder and electro coat techniques, without being limited to these, and may be cured using, e.g., convection curing, infrared curing, both continuous and pulsed, as defined herein, or UV curing, without being limited to these.

As used herein, the term “primer coat” refers to an undercoating layer that can be applied onto a substrate, including a bare substrate, in order to prepare the surface for application of a protective or decorative coating composition.

As used herein, the term “basecoat” refers to a coating layer that is applied onto a primer, another basecoat layer; and/or directly onto a substrate, optionally including components (such as colorants as described above) that impact the color and/or provide other visual impact. The coating composition described above may be applied as the outermost layer over an existing cured clearcoat layer.

The method disclosed herein makes to possible to apply the above-described coating composition over only a part of the surface of the substrate without the need for masking those parts of the surface which shall not be coated with said composition with a removable material, such as taping material.

In the present method the coating composition may be applied as a continuous jet, as continuous stream of droplets and/or as a drop-on demand. As used herein, the term “continuous jet” refers to a continuous coating composition stream exiting a precision applicator which is applied to a substrate to provide a knife edge line where the applied coating ends. As used herein the terms “drop” and “droplet” refer to a column of liquid, bounded completely by free surfaces. As used herein, the term “continuous stream of droplets” refers to a plurality of droplets of coating exiting a precision applicator that are applied far enough apart to reduce the material volume applied in comparison to a continuous jet, yet close enough to flow together and provide conformal coating coverage. As used herein, “drop on demand” refers to a precision applicator that controls the volume of a single drop and only dispenses such a drop when indicated to do so.

In the present method the above-described coating composition is cured by applying pulsed infrared radiation having a peak wavelength in the range of from 3 pm to 10 pm at a pulse duration of less than 100 ps to the coating composition, which is applied to at least a part of a surface of a substrate.

As used herein, the term “peak wavelength” refers to the maximum emission wavelength of the pulsed infrared radiation. The pulsed infrared radiation used in present the method may have a peak wavelength of 6 pm or less, or of 4 pm or less. The pulsed infrared radiation may be in the range of from 3 pm to 6 pm or of from 3 pm to 4 pm.

As used herein, the term “pulsed” refers to radiation that is emitted in time-limited portions (the pulses). The term “infrared radiation” refers to electromagnetic radiation having a wavelength in the range of 780 nm to 1 mm. Accordingly, the term “pulsed infrared radiation” refers to electromagnetic radiation having a wavelength in the infrared spectral range, which is applied in pulses. The pulses may have a pulse duration at a pulse frequency.

As used herein, the term “pulse duration” which is also referred to as “pulse width”, refers to the full-width at half maximum (FWHM) amplitude of a pulse of the pulsed infrared radiation. The pulsed infrared radiation may be applied at a pulse duration of at least 5 ps, such as at least 7 ps, or at least 8 ps, or at least 10 ps. The pulsed infrared radiation may be applied at a pulse duration of 75 ps or less, such as 50 ps or less, or 25 ps or less, or 17 ps or less, or 14 ps or less. The pulsed infrared radiation may be applied at a pulse duration ranging from 7 ps to 14 ps, or from 8 ps to 14 ps, or from 10 ps to 14 ps, or from 7 ps to 17 ps, or from 8 ps to 17 ps, or from 10 ps to 17 ps, or from 7 ps to 25 ps, or from 8 ps to 25 ps, or from 10 ps to 25 ps, or from 7 ps to 50 ps, or from 8 ps to 50 ps, or from 10 ps to 50 ps, or from 7 ps to 75 ps, or from 8 ps to 75 ps, or from 10 ps to 75 ps. The pulsed infrared radiation may be applied at a pulse duration in a range between any of the above-mentioned values such as from 7 ps to 75 ps, such as from 7 ps to 50 ps, such as from 8 ps to 25 ps, such as from 10 ps to 17 ps, such as from 10 ps to 14 ps.

The terms “cure”, “cured” or similar terms, as used in connection with the coating composition described herein, means that at least a portion of the components that form the coating composition is crosslinked to form a coating. The pulsed infrared radiation may be applied to the coating composition to form an at least partially cured coating. As used herein, the term “at least partially cured coating” means that the reaction of at least a portion of the reactive groups of the components of the coating composition occurs. The pulsed infrared radiation may be applied to the coating composition to form a full cured coating. Full cure is attained when further curing results in no significant further improvement in the coating properties. Cure, or the degree of cure, may also be determined by dynamic mechanical thermal analysis (DMTA) using a Polymer Laboratories MK III DMTA analyzer conducted under nitrogen in which the degree of cure may for example be at least 10%, such as at least 30%, such as at least 50%, such as at least 70%, or at least 90% of complete crosslinking as determined by DMTA. The coating composition may be cured by applying the 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 may be cured by applying the 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 the pulsed infrared radiation may range between any of the above-mentioned values. For instance, the coating composition may be cured by applying the pulsed infrared radiation for a total time of from 30 sec to 10 min, or of from 30 sec to 5 min, or of from 1 min to 3 min. As used herein, the term "total time for curing the coating composition by applying the pulsed infrared radiation" refers to the whole time during which the pulsed radiation is applied, including both the pulse-on and the pulse-off states. In comparison to an oven cure, shorter curing times may be achieved resulting in energy savings. The method further provides high efficiency, as the infrared radiators are active shortly after switching on, without a long preheating period, and only desired partial areas are heated, e.g., the substrate having applied the coating composition.

Without intending to be bound by a specific theory, using pulsed infrared radiation, the transfer of energy to the coating composition is not primarily realized by thermal convection or thermal conduction, but by non-visible electromagnetic waves in the infrared spectral range at the speed of light, because electromagnetic waves propagate in the same way and at the same speed as light waves. Infrared radiation penetrates quickly and effectively into the surface of the substrate and ensures rapid curing of the applied coating composition. This enables the transfer of a radiation with high energy density and thus an energetically highly efficient curing of the coating. Faster and more energyefficient curing at rather low surface temperatures of the substrate, such a less, for instance, than 130 °C, and even lower temperatures within the substrate's body, may be achieved in comparison to thermal methods, even when curing coatings having a thickness of 75 pm or more. In combination with the precision application this efficiently prevents running and sagging of the applied coating compositions. In addition to accelerated curing, the use of pulsed infrared may impart enhanced physical and/or chemical properties to the cured coating formed from the above-described coating composition. The enhanced physical and/or chemical properties may include at least one of microhardness, scratch and mar resistance, chemical resistance towards at least one of acids, enzymes 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 is applied, e.g., a force in the range from 0.01 N to 10 N. Microhardness may 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 from impact, rubbing or abrasion that produces visible scratches or marring. Scratch and mar resistance may 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, e.g., discoloration, alteration in the degree of shine, softening, swelling, detachment of coatings or blistering. Chemical resistance towards at least one of acids, enzymes and tree sap, or a combination thereof may be determined according to DIN EN ISO 2812-5:2018.

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

The pulsed infrared radiation may 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 may be applied at a pulse frequency of 450 Hz or less, such as 430 Hz. The pulsed infrared radiation may be applied at a pulse frequency in the range of from 350 Hz to 450 Hz, such as from 350 Hz to 430 Hz, or from 370 Hz to 450 Hz, or from 370 Hz to 430 Hz, or from 390 Hz to 450 Hz, or from 390 Hz to 430 Hz, or from 400 Hz to 450 Hz, or from 400 Hz to 430 Hz. The pulsed infrared radiation may be applied at a pulse frequency in the range of from 350 Hz to 450 Hz, such as from 370 Hz to 450 Hz, such as from 390 Hz to 430 Hz, such as from 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.

The pulsed infrared radiation may be applied at an impulse energy of at least 250 W/cm², such as at least 270 W/cm², or at least 290 W/cm². The pulsed radiation may be applied at an impulse energy of 350 W/cm² or less, such as 330 W/cm² or less, or 320 W/cm² or less. The pulsed infrared radiation may be applied at an impulse energy in the range between any of the above-mentioned values such as from 250 W/cm² to 350 W/cm², or from 250 W/cm² to 330 W/cm², or from 250 W/cm² to 320 W/cm², or from 270 W/cm² to 350 W/cm², or from 270 W/cm² to 330 W/cm², or from 270 W/cm² to 320 W/cm², or from 290 W/cm² to 350 W/cm², or from 290 W/cm² to 330 W/cm², or from 290 W/cm² to 320 W/cm². As used herein, the term “impulse energy” refers to the total radiant power of electromagnetic radiation received by a surface per unit area.

The pulsed infrared radiation may be provided by an infrared light source comprising a surface which comprises a ceramic composition. The ceramic composition may be capable of absorbing heat and emitting infrared radiation having a peak wavelength in the range of from 3 pm to 10 pm. An infrared light source may comprise a surface which comprises a ceramic composition capable of absorbing heat and emitting infrared radiation having a peak wavelength in the range of from 3 pm to 10 pm.

For curing, the infrared radiation emitting surface of the infrared light source may face the surface of the substrate having applied the coating composition to be cured. Herein, the distance between the infrared emitting surface of the infrared light source and the surface of the substrate having applied the coating composition to be cured may be at 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 having applied the coating composition to be cured may be at a distance of 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 may face the surface of the substrate having applied the coating composition to be cured at a distance in a range between any of the above-mentioned values, such as from 5 cm to 50 cm, such as from 5 cm to 45 cm, such as from 5 to 40 cm, such as from 5 to 35 cm, such as from 5 to 30 cm, such as from 5 to 25 cm, such as from 10 cm to 50 cm, such as from 10 cm to 45 cm, such as from 10 to 40 cm, such as from 10 to 35 cm, such as from 10 to 30 cm, such as from 10 to 25 cm, such as from 15 cm to 50 cm, such as from 15 cm to 45 cm, such as from 15 to 40 cm, such as from 15 to 35 cm, such as from 15 to 30 cm, such as from 15 to 25 cm.

The infrared light source may face the surface of the substrate having applied the coating composition to be cured at least from one side. At least one or more infrared light source(s) may surround the substrate having applied the coating composition to be cured 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 pages 12 and 13, the specified disclosure of which is incorporated herein by reference. The infrared light source may have any desired shape, such as a shape of a rod, a tube, a flat plate or a curved plate.

The infrared light source may further comprise a heat source for directly or indirectly heating up the ceramic composition. Heat transfer from the heat source may include various ways of heat transfer, including radiation transfer, convection, contact transfer or a transfer via thermally conductive materials in between the heat source and the ceramic composition. The infrared light source may further comprise a carrier material for heat absorption and/or heat transfer from the heat source to the ceramic composition. The carrier material may comprise one or more of the following materials: Fe; SiC ; 3Al2Os-2SiO2 and/or 2AI2O3 I SiC>2 (mullite); Al or Cu. Further, the infrared light source may comprise a reflector device. The ceramic composition may generate infrared light and emit the infrared light, inter alia, into an unwanted direction. The reflector device, which may comprise one or more reflectors, may be applied to reflect the infrared light emitted in unwanted directions and re-direct said infrared light in a certain area, e.g., to the surface of the substrate having applied the coating composition to be cured. The ceramic composition may 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, the lanthanides and actinides, and (a-ii) oxygen; and (b) a mullite remainder component comprising 3Al2O3'2SiO2 and/or 2Al2Os SiO2 (mullite). Suitable examples of a metal oxide component (a) include, but are not limited to, O2O3, ZrC>2, HO2O3, Fe2Os, LaCrOs, CeC>2, Y2O3, YCrOs, Gd2C>3, MgAI₂O4, MgCrC , CaCrC , YCrOs, CuO, La2Os, CuCrC>4 and FeCrOs.

The ceramic composition may consist of a metal oxide component (a) and a mullite remainder component (b).

The ceramic composition may 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 may 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 may comprise the metal oxide component (a) in a range of from 0.1 to 70.0 wt.%, or from 0.5 to 70.0 wt.%, or from 1 .0 to 70.0 wt.%, or from 5.0 to 70.0 wt.%, or 0.1 to 60.0 wt.%, or 0.5 to

60.0 wt.%, or 1 .0 to 60.0 wt.%, or 5.0 to 60.0 wt.%, or 0.1 to 50.0 wt.%, or 0.5 to

50.0 wt.%, or 1 .0 to 50.0 wt.%, or 5.0 to 50.0 wt.%, or 0.1 to 40.0 wt.%, or 0.5 to

40.0 wt.%, or 1 .0 to 40.0 wt.%, or 5.0 to 40.0 wt.%, or 0.1 to 30.0 wt.%, or 0.5 to

30.0 wt.%, or 1 .0 to 30.0 wt.%, or 5.0 to 30.0 wt.%, or 0.1 to 20.0 wt.%, or 0.5 to

20.0 wt.%, or 1 .0 to 20.0 wt.%, or 5.0 to 20.0 wt.%, based on the total weight of the ceramic composition. The ceramic composition may comprise the metal oxide component (a) in a range of from 0.1 to 70.0 wt.%, such as from 0.5 to 60.0 wt.%, such as from 0.5 to 50.0 wt.%, such as from 1 .0 to 40.0 wt.%, such as from 1 .0 to 30.0 wt.%, such as from 5.0 to 20.0 wt.%, based on the total weight of the ceramic composition.

The ceramic composition may 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 may 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 may comprise the mullite remainder component (b) in a range of from 30.0 to

99.9 wt.%, or from 30.0 to 99.5 wt.%, or from 30.0 to 99.0 wt.%, or from 30.0 to 95.0 wt.%, or from 40.0 to 99.9 wt.%, or 40.0 to 99.5 wt.%, or 40.0 to 99.0 wt.%, or 40.0 to 95.0 wt.%, or 50.0 to 99.9 wt.%, or 50.0 to 99.5 wt.%, or 50.0 to 99.0 wt.%, or 50.0 to 95.0 wt.%, or 60.0 to 99.9 wt.%, or 60.0 to 99.5 wt.%, or 60.0 to 99.0 wt.%, or 60.0 to 95.0 wt.%, or 70.0 to 99.9 wt.%, or 70.0 to 99.5 wt.% or 70.0 to 99.0 wt.%, or 70.0 to 95.0 wt.%, or 80.0 to 99.9 wt.%, or 80.0 to

99.5 wt.%, or 80.0 to 99.0 wt.%, or 80.0 to 95.0 wt.%, based on the total weight of the ceramic composition. The ceramic composition may comprise the mullite remainder component (b) in a range of from 30.0 to 99.9 wt.%, or from 40.0 to 99.9 wt.%, or from 50.0 to 99.5 wt.%, or from 60.0 to 99.0 wt.%, or from 70.0 to 95.0 wt.%, or 80.0 to 95.0 wt.%, based on the total weight of the ceramic composition.

The ceramic compositions may be processed by standard ceramic processing procedure known to a person skilled in the art. The ceramic composition may be milled by conventional milling procedures, such as arc milling, to a fine powder, mixed until homogeneity is achieved, and melted, typically at temperatures of 2.600 °C. The melting may be carried out in an oxidizing atmosphere, e.g., in air. The resulting melted material may be ground to a grain size, e.g., in the range of 100 to 250 pm and then the powder may be formed into a desired shape. A suitable procedure of processing ceramic compositions is disclosed in, e.g., WO 99/01401 A1 . The process of forming the ceramic composition may include high-pressure treatment of the ceramic composition using a press and shaping a formed body of the object to be generated of the ceramic composition. The process of shaping the ceramic composition into an object may further include further temperature treatments, such as sintering process, and, optionally, further pressurizing processes. Shaping of the ceramic compositions to form arbitrary objects may include standard shaping procedures, such as mechanical treatment, powder processes, or ceramic injection molding. Thus, the ceramic composition may be formed by standard ceramic forming procedures into nearly arbitrary shape.

The combination of applying the coating combination by precision application and subsequently curing the applied coating using pulsed infrared radiation makes it possible to apply a coating of relatively high thickness in one pass.

The cured coating may 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 1 10 pm, or more. The cured coating may have a thickness ranging 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 cured coating may have a thickness ranging between any of the above-mentioned values, such as from 75 pm to 200 pm, or of from 80 pm to 180 pm, or of from 90 pm to 160 pm, or of from 95 pm to 150 pm, or of from 100 pm to 140 pm, or of from 105 pm to 130 pm, or of from 1 10 pm to 120 pm. The thickness can be determined according to DIN EN ISO 2178:2016.

The substrate to which the protective coating is applied by the method described above may be, without being limited thereto, a vehicle, a storage tank, a windmill, a package, wood flooring and furniture, apparel, electronics, glass and transparencies, sports equipment, a building, a bridge, or a part thereof, in particular a vehicle or a part thereof.

The term “vehicle” is used herein in its broadest sense and includes (without limitation) all types of aircraft, spacecraft, watercraft, and ground vehicles. For example, a vehicle may include, aircraft such as airplanes including private aircraft, and small, medium, or large commercial passenger, freight, and military aircraft; helicopters, including private, commercial, and military helicopters; aerospace vehicles including, rockets and other spacecrafts. Vehicles may include ground vehicles such as, for example, trailers, cars, trucks, buses, coaches, vans, ambulances, fire engines, motorhomes, caravans, go-karts, buggies, fork-lift trucks, sit-on lawnmowers, agricultural vehicles such as, for example, tractors and harvesters, construction vehicles such as, for example, diggers, bulldozers and cranes, golf carts, motorcycles, bicycles, trains, and railroad cars. Vehicles may also include watercraft such as, for example, ships, submarines, boats, jet-skis and hovercraft.

For instance, the protective coating may be applied over at least a part of one or more of the body, underbody, hood, fender, mudguard, mirror cover, boot sill trim, bumper, front apron, grille, running board, handle, spoiler and side skirt of a vehicle, such as a ground vehicle, such as a car.

The present disclosure further relates to a coated substrate obtained by the method described above. Herein, the substrate may be a substrate as defined above.

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

Herein, the coating composition may be a coating composition as described above.

The substrate may be a substrate as defined above.

The protective coating may be applied to at least a part of the substrate using the processes and devices described above.

The pulsed infrared radiation may be applied using the processes and devices described above.

The protective coating may be a coating protecting a vehicle's paint against abrasion, wear debris and stone chipping.

ASPECTS

The following clauses summarize some aspects of the present application. A first aspect of the present application relates to a method for applying a protective coating to a substrate, the method comprising:

(i) applying a fluid coating composition over at least a part of a surface of the substrate by precision application substantially without overspray, wherein the coating composition comprises a film-forming resin and a crosslinking agent suitable for crosslinking the film-forming resin; and

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

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

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

A fourth aspect of the present application relates to the method of any one 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 crosslinking agent comprises a polyisocyanate.

A fifth aspect of the present application relates to the method of any one of the preceding aspects, wherein the coating composition further comprises an UV light absorber, a hindered amine light stabilizer, a catalyst, a rheology modifier, a sag control agent, a scratch- and mar-resistance additive, a defoaming additive, a leveling additive, or any combinations thereof.

A sixth aspect of the present application relates to the method of any one of the preceding aspects, wherein (i) the coating composition is applied over a part of a substrate having an existing coating on the surface over which the coating composition is applied. A seventh aspect of the present application relates to the method of the sixth aspect, wherein the existing coating is a cured multi-layer coating.

An eighth aspect of the present application relates to the method of the sixth or seventh aspect, wherein the coating composition is applied as the outermost layer over a cured clearcoat layer.

A ninth aspect of the present application relates to the method of any one of the preceding aspects, wherein (i) the coating composition is applied over a part of the surface without masking those parts of the surface not to be coated by the coating composition with a removable material.

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

An eleventh aspect of the present application relates to the method of any one of the preceding aspects, wherein the pulsed infrared radiation has a peak wavelength in the range of from 3 pm to 6 pm or of from 3 pm to 4 pm.

A twelfth aspect of the present application relates to the method of any one of the preceding aspects, wherein the pulsed infrared radiation is applied at a pulse duration ranging from 7 ps to 17 ps or from 10 ps to 14 ps.

A thirteenth aspect of the present application relates to the method of any one of the preceding aspects, wherein the pulsed infrared radiation is applied at a pulse frequency of from 350 Hz to 450 Hz or of from 400 Hz to 450 Hz.

A fourteenth aspect of the present application relates to the method of any one of the preceding aspects, wherein the pulsed infrared radiation is applied at an impulse energy of from 250 W/cm² to 350 W/cm² or of from 290 W/cm² to 320 W/cm². A fifteenth aspect of the present application relates to the method of any one of the preceding aspects, wherein the pulsed infrared radiation is provided by an infrared light source comprising a surface which comprises a ceramic composition capable of absorbing heat and emitting infrared radiation having a peak wavelength in the range of from 3 pm to 10 pm.

A sixteenth aspect of the present application relates to the method of any one of the preceding aspects, wherein (ii) the coating is cured by applying the pulsed infrared radiation for a total time of from 30 sec to 5 min or of from 1 min to 3 min.

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

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

A nineteenth aspect of the present application relates to the method of the eighteenth aspect, wherein the protective coating is applied over at least a part of one or more of the body, underbody, hood, fender, mudguard, mirror cover, boot sill trim, bumper, front apron, grille, running board, handle, spoiler and side skirt of a vehicle.

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

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

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

A twenty-third aspect of the present application relates to the use of 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.

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

A twenty-fifth aspect of the present application relates to the use of 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.

A twenty-sixth aspect of the present application relates to the use of any one of the twenty-first to twenty-fifth aspects, wherein the protective coating is a coating protecting a vehicle's paint against abrasion, wear debris and stone chipping.

EXAMPLES

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

Component A was prepared by mixing the compounds given in Table 1 below. 1 14 g of Component A, 57.6 g of HDI, present as a mixture of uretdione, trimer and homopolymer, all commercially available from Covestro (Germany) under the tradename Desmodur®, as Component B, and 36.8 g of butyl acetate were then combined and mixed thoroughly, to give 2K clearcoat coating composition having a molar ratio of isocyanate to hydroxyl groups of 1 .2:1 .0 or 1 .0:1 .0. Table 1 : Component A for protective 2K Clearcoat Coating Composition

¹ Hydroxyl number [mg KOH/g, DIN 53240, 2007-11]: 280; acid number [mg KOH/g, ISO 2114]: 85; solids content [%]: 70, Tg [°C, ASTMD3418-03]: 18; viscosity [mPa-s; 23 °C, D = 1000 s’¹, DIN EN ISO 3219/A3]: 4400

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

³ OH%: 4.5; solids content: 60; viscosity 1250

⁴ Tinuvin 928, commercially available from BASF (Germany)

⁵ Tinuvin 123, commercially available from BASF (Germany) ⁶ BYK-322 commercially available from Byk (Germany)

⁷ BYK-390 commercially available from Byk (Germany)

⁸ Dibutyltin dilaurate (1% solution in butyl acetate)

⁹ N-butyl acetate; ethyl 3-ethoxypropionate; n-butanol

¹⁰ fumed silica paste, anti-scratch additives In order to prepare panels for the application of the above protective 2K coating composition, steel panels coated with a PPG electrodeposition coating (commercially available from ACT panels of Hillsdale, Ml, USA) were painted by an electrostatic rotary bell applicator in a 3-coating layer stack. The 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 second flash, the same process was repeated for the second basecoat (Alpine White waterborne basecoat BIPCU300 available from PPG Industries, Inc. (Pittsburgh, PA, USA)) at a thickness of about 15 to 18 pm, and after a room temperature flash for 335 seconds, the panels were dehydrated for 6 minutes at 74°C, Finally, a clearcoat (TKAPO 1 100A and TKAPO B pack commercially available from PPG Industries, Inc, (Pittsburgh, PA, USA)) was applied at a thickness of about 15 pm for the first pass and 35 pm for the second pass with a 1 minute flash in between. After a 10-minute flash the panels were cured at 140°C for 30 minutes.

These panels were then overcoated in a horizontal position with the above protective 2K coating composition using an EcoPaintJet precision applicator with a 056 nozzle plate (available from Durr Systems AG (Bietigheim-Bissingen, Germany)) using a tip speed of 650 mm/s and a flow rate of about 480 mL/min.

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

Table 2:

Claims

1 . A method for applying a protective coating to a substrate, the method comprising:

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 clearcoat composition.

3. The method of any one 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 crosslinking agent comprises a polyisocyanate; and/or wherein the coating composition further comprises an UV light absorber, a hindered amine light stabilizer, a catalyst, a rheology modifier, a sag control agent, a scratch- and mar-resistance additive, a defoaming additive, a leveling additive, or any combinations thereof.

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

5. The method of claim 4, wherein the existing coating is a cured multi-layer coating.

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

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

8. The method of any one of the preceding claims, wherein the pulsed infrared radiation has a peak wavelength in the range of from 3 pm to 6 pm or of from 3 pm to 4 pm; and/or wherein the pulsed infrared radiation is applied at a pulse duration ranging from 7 ps to 17 ps or from 10 ps to 14 ps; and/or wherein the pulsed infrared radiation is applied at a pulse frequency of from 350 Hz to 450 Hz or of from 400 Hz to 450 Hz; and/or wherein the pulsed infrared radiation is applied at an impulse energy of from 250 W/cm² to 350 W/cm² or of from 290 W/cm² to 320 W/cm².

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

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

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

12. The method of claim 11 , wherein the protective coating is applied over at least a part of one or more of the body, underbody, hood, fender, mudguard, mirror cover, boot sill trim, bumper, front apron, grille, running board, handle, spoiler and side skirt of a vehicle.

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

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

15. The use of 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 part of the 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 protecting a vehicle's paint against abrasion, wear debris and stone chipping.