The present invention relates to a peelable coating system comprising a first coating layer being prepared from a solvent-based coating composition comprising a mixture of polyvinylaromatic-polydiene block copolymer(s), rubber copolymer(s) and alicyclic hydrocarbon resin(s), a second coating layer being prepared from a pigmented basecoat composition and a third coating layer being prepared from clearcoat or tinted clearcoat composition. The coating system has good optical and mechanical properties and can be easily peeled residue free from the substrate without a negative impact on the underlying substrate. The present invention moreover relates to a method for forming a peelable coating system onto at least part of a surface of a substrate and a coated substrate prepared according to the inventive method.

State of the art

There is a need in the automotive market to personalize the automotive in terms of color and/or pattern, for example by temporarily changing the color and/or temporarily painting a personalized pattern onto the automobile, without damaging the original finish (e.g. original multilayer coating) of the automobile.

It is known in the state of the art to temporarily color or pattern an automobile without damaging the original finish using colored plastic films, such as colored foils. However, glue and pulling force may be needed during attachment of the plastic film to the automobile surface since the plastic film is planar, while the automobile has a three- dimensional structure. Moreover, debonding and upwarping of the plastic film may occur at the edge of the automobile body due to shrinkage tendency of the plastic film, thus damaging the overall appearance of the temporarily changed automobile surface. In addition, the attached plastic films are difficult to peel from the automobile surface and residual glue remaining on the automobile surface after peeling is hard to remove without damaging the original finish of the automobile. Finally, the plastic films are not available in all colors commonly used in the automotive industry, thus restricting the number of available colors usable for personalization of the automobile. Therefore, efforts have been made to design a peelable coating system that can replace the use of colored plastic films to temporarily change the appearance of automobiles.

U.S. Pat. No. 6,458,441 B1 discloses a single-layer peelable coating material consisting of a solvent-free aqueous anionic polyurethane-polyurea dispersion. The coating formed from the peelable coating material has the advantages of good ductility, and high tensile strength, is easy to peel off, and can be fitted on any cambered surface. Meanwhile, the coating also has the disadvantage of poor adhesion on the surface of products, and is easy to fall off.

In order to solve the problem of easily falling off of the peelable coating, US2014087070A1 discloses a multilayer peelable coating system comprising a primer layer formed of a heat activated adhesive, and a cover layer on the surface of the primer layer formed from an aqueous polymer system. Since the activation temperature required for the heat activated adhesive greatly exceeds the operation temperature of the automobile industry, the above multilayer peelable coating system is not suitable for use in the automobile industry.

US2012276381 A1 discloses a multilayer peelable coating system comprising a primer layer formed of an acrylic resin system, and a cover layer on the surface of the primer layer formed from an aqueous polyurethane system. However, the cover layer formed from the aqueous polyurethane system has low hardness, and thus cannot meet the polishability requirement on automobile coatings.

Thus, there still remains a need to provide a peelable coating system having a high quality optical appearance, sufficient mechanical stability, sufficient adhesion to the original finish and that is suitable for substrates of various materials and shapes.

Object

Accordingly, an object of the present invention is to provide peelable coating systems resulting in a high quality optical appearance and having sufficient mechanical stability to prevent damage of the peelable coating system from environmental influences, such as humidity, stone chipping, washing, etc., during the life-time of the peelable coating system on the automobile. Moreover, the peelable coating system should be available in all colors commonly used in the automotive industry. Finally, the peelable coating system should have a sufficient adhesion to the original finish to avoid a negative influence on the overall optical appearance but should, at the same time, be peelable from the original finish, in particular by hand, without damaging the original finish and without leaving excess amounts of residues on the original finish.

Technical solution

The objects described above are achieved by the subject matter claimed in the claims and also by the preferred embodiments of that subject matter that are described in the description hereinafter.

A first subject of the present invention is therefore a peelable coating system comprising

(a) a first coating layer (CL-1) being prepared by applying a first coating composition (C-1) to at least part of a surface of a substrate (S), said first coating composition (C-1) comprising

(a-1 ) at least one polyvinylaromatic-polydiene block copolymer,

(a-2) at least one rubber copolymer being different from copolymer (a-1 ),

(a-3) at least one alicyclic hydrocarbon resin and (a-4) at least one organic solvent;

(b) a second coating layer (CL-2) being prepared by applying a second coating composition (C-2) to the first coating layer (CL-1), said second coating composition (C-2) comprising at least one pigment (b-1) and at least one binder (b-2); and

(c) a tinted clearcoat and/or tinted clearcoat layer (CL-3) being prepared by applying a tinted clearcoat and/or a clearcoat coating composition (C-3) to the second coating layer (CL-2); wherein the first coating layer (CL-1), the second coating layer (CL-2) and the third coating layer (CL-3) form a peelable coating, wherein an adhesive strength between the first coating layer (CL-1), the second coating layer (CL-2) and the third coating layer (CL-3) is greater than an adhesive strength between the first coating layer (CL-1 ) and the surface of the substrate (S). The above-specified peelable coating system is hereinafter also referred to as peelable coating system of the invention and accordingly is a subject of the present invention. Preferred embodiments of the peelable coating system of the invention are apparent from the description hereinafter and also from the dependent claims.

In light of the prior art it was surprising and unforeseeable for the skilled worker that the objects on which the invention is based could be achieved by using a first coating composition comprising a mixture of polyvinylaromatic-polydiene block copolymer(s), rubber copolymer(s) and alicyclic hydrocarbon resin(s). The first coating layer resulting from this composition has sufficient adhesion to the underlying substrate and can be overcoated with commonly used pigmented basecoat compositions and clearcoat or tinted clearcoat compositions without a negative influence on the resulting optical and mechanical properties of the peelable coating system. Since commonly used pigmented basecoat compositions can be applied, the inventive peelable coating system provides a color variety with is significantly larger than the one provided by colored plastic films. This also allows to use colors specifically designed for temporarily customizing the substrate, such as company colors or the like. Moreover, the adhesion between the first coating layer, the pigmented basecoat layer and the clearcoat or tinted clearcoat layer is higher than the adhesion of the first coating layer to the substrate, thus allowing to peel the resulting multilayer coating from the substrate substantially residue free. The required peeling strength is rather low such that peeling can be performed by hand. The inventive peelable coating system has sufficient mechanical stability during its lifetime, such that the optical appearance is not damaged by environmental influences, such as humidity, car washing and stone chipping. This avoids early removal of the damaged peelable coating system and thus higher costs associated with the early removal and reattachment of a new peelable coating system.

A further subject of the present invention is a method for forming a peelable coating system onto at least part of a surface of a substrate, said method comprising

(i) applying the first coating composition (C-1) to at least part of a surface of the substrate and optionally drying the applied first coating composition (C-1 ) to form a first coating film (CF-1 ),

(ii) curing the formed first coating film (CF-1 ) to form a first coating layer (CL-1 ), (iii) applying the second coating composition (C-2) on at least part of the first coating layer (CL-1) and optionally drying the applied second coating composition (C-2) to form a second coating film (CF-2),

(iv) applying the third coating composition (C-3) on at least part of the second coating film (CF-2) to form a third coating film (CF-3), and

(v) jointly curing the second coating film (CF-2) and the third coating film (CF-3) to form a second coating layer (CL-2) and a third coating layer (CL-3), wherein the first coating layer (CL-1), the second coating layer (CL-2) and the third coating layer (CL-3) form a peelable coating, wherein an adhesive strength between the first coating layer (CL-1), the second coating layer (CL-2) and the third coating layer (CL-3) is greater than an adhesive strength between the first coating layer (CL-1 ) and the surface of the substrate (S).

A further subject of the present invention is a coated substrate obtained by the inventive method.

Detailed description

Definitions:

First of all, a number of terms used in the context of the present invention will be explained.

A “copolymer” in the context of the present invention refers to a polymer formed from different polymers or monomers. This explicitly includes both polymers/monomers bonded covalently to one another and those in which the different polymers are bound to one another by adhesion. Combinations of the two types of bonding are also covered by this definition.

“Polyvinylaromatic-polydiene block copolymer” refers to block copolymers comprising polyvinylaromatic blocks as well as polydiene blocks, which are preferably covalently bonded to each other. The copolymers may have a diblock or a triblock structure and the polydiene blocks may be at least partially hydrogenated. “Rubber copolymer” refers to copolymers comprising at least two different petroleum- based monomers, such as isoprene, butadiene, styrene, 2-chlorobutadiene or mixture thereof.

“Alicyclic hydrocarbon resin” refers to resins (e.g. homo- or copolymers, in particular copolymers) having at least one alicyclic ring in the main skeleton of the resin. Such resins can be obtained, for example, by polymerizing a C6 to C20 fraction of the naphtha cracked oil fraction and optionally at least partially hydrogenating the resulting polymer.

A “binder” in the context of the present invention and in accordance with DIN EN ISO 4618:2007-03 is the nonvolatile component of a coating composition, without pigments and fillers. Hereinafter, however, the expression is used principally in relation to particular physically and/or thermally curable polymers, examples being polyurethanes, polyesters, polyethers, polyureas, polyacrylates, polysiloxanes and/or copolymers of the stated polymers. The nonvolatile fraction may be determined according to DIN EN ISO 3251 : 2018-07 at 130°C for 60 min using a starting weight of 1.0 g.

“Drying” of an applied coating composition refers to the evaporation of solvents from the applied coating composition. Drying can be performed at ambient temperature or by use of elevated temperatures. However, the drying does not result in a coating film being ready for use, i.e. a cured coating film as described below, because the coating film is still soft or tacky after drying. Accordingly, “curing” of a coating film refers to the conversion of such a film into the ready-to-use state, i.e. into a state in which the substrate provided with the respective coating film can be transported, stored and used as intended. More particularly, a cured coating film is no longer soft or tacky, but has been conditioned as a solid coating film which does not undergo any further significant change in its properties, such as hardness or adhesion to the substrate, even under further exposure to curing conditions. Curing can be performed at higher temperatures and/or for longer times than used for drying of the coating composition.

The measurement methods to be employed in the context of the present invention for determining certain characteristic variables can be found in the Examples section. Unless explicitly indicated otherwise, these measurement methods are to be employed for determining the respective characteristic variable. Where reference is made in the context of the present invention to an official standard without any indication of the official period of validity, the reference is implicitly to that version of the standard that is valid on the filing date, or, in the absence of any valid version at that point in time, to the last valid version.

All film thicknesses reported in the context of the present invention should be understood as dry film thicknesses. It is therefore the thickness of the cured film in each case. Hence, where it is reported that a coating material is applied at a particular film thickness, this means that the coating material is applied in such a way as to result in the stated film thickness after curing.

All temperatures elucidated in the context of the present invention should be understood as the temperature of the room in which the substrate or the coated substrate is located. It does not mean, therefore, that the substrate itself is required to have the temperature in question.

Inventive peelable coatinq system:

Substrate (S):

The first coating layer (CL-1) of the inventive peelable coating layer is formed on at least part of the surface of a substrate (S). Suitable substrates (S) include metallic substrates optionally coated with at least one cured coating layer, plastic substrates optionally coated with at least one cured coating layer, substrates comprising metallic and plastic components and optionally coated with at least one cured coating layer, preferably from metallic substrates coated with at least one cured coating layer, in particular from metallic substrates coated with a cured multilayer coating. Metallic substrate may be selected from the group comprising or consisting of iron, aluminum, copper, zinc, magnesium and alloys thereof as well as steel.

Coated and uncoated metal substrates can be pretreated in a manner known per se, i.e. , for example, cleaned and/or provided with known conversion coatings. Cleaning can be performed mechanically, for example by means of wiping, grinding and/or polishing, and/or chemically by means of etching methods, such as surface etching in acid or alkali baths using, for example, hydrochloric acid or sulfuric acid, or by cleaning with organic solvents or aqueous detergents. Pretreatment by application of conversion coatings, especially by means of phosphation and/or chromation, preferably phosphation, may likewise take place. Preferably, the metallic substrates are at least conversion-coated, especially phosphated, preferably by a zinc phosphation.

Metal substrates being coated with a cured electrocoat are produced by electrophoretic application of an electrocoat material to the substrate and subsequent curing of the applied electrocoat material. The electrocoat material may be a cathodic or anodic electrocoat material, preferably a cathodic electrocoat material. Electrocoat materials are aqueous coating materials comprising anionic or cationic polymers as binders. These polymers contain functional groups which are potentially anionic, i.e. can be converted to anionic groups, for example carboxylic acid groups, or functional groups which are potentially cationic, i.e. can be converted to cationic groups, for example amino groups. The conversion to charged groups is generally achieved by the use of appropriate neutralizing agents (organic amines (anionic), organic carboxylic acids such as formic acid (cationic). The electrocoat materials generally comprise typical anticorrosion pigments. The cathodic electrocoat materials preferred in the context of the invention comprise preferably cationic polymers as binders, especially hydroxy- functional polyether amines, which preferably have aromatic structural units. These polymers are especially used in combination with blocked polyisocyanates known per se. The application of the electrocoating material proceeds by electrophoresis. For this purpose, the metallic workpiece to be coated is first dipped into a dip bath containing the coating material, and an electrical DC field is applied between the metallic workpiece and a counterelectrode. The workpiece thus functions as an electrode; the nonvolatile constituents of the electrocoat material migrate, because of the described charge of the polymers used as binders, through the electrical field to the substrate and are deposited on the substrate, forming an electrocoat film. For example, in the case of a cathodic electrocoat, the substrate is thus connected as the cathode, and the hydroxide ions which form there through water electrolysis neutralize the cationic binder, such that it is deposited on the substrate and forms an electrocoat layer. After the electrolytic application of the electrocoat material, the coated substrate is removed from the bath, optionally rinsed off with, for example, water-based rinse solutions, then optionally flashed off and/or intermediately dried, and finally cured. The dry film thickness of the cured electrocoat is, for example, 10 to 40 micrometers, preferably 15 to 25 micrometers.

Metal substrates being coated with a cured filler layer are produced by applying a filler coating composition to the substrate, optionally flashing off and/or intermediately drying said applied composition and finally curing said composition. Suitable filler coating compositions are known in the state of the art. The dry film thickness of the cured filler layer is, for example, 10 to 40 micrometers, preferably 25 to 30 micrometers.

Metal substrates being coated with a cured basecoat and clearcoat or tinted clearcoat layer are produced by applying a basecoat coating composition to the substrate, optionally flashing off and/or intermediately drying said applied composition, applying a clearcoat composition wet-on-wet on the uncured basecoat film and finally jointly curing the basecoat and the clearcoat film. Suitable basecoat and clearcoat or tinted clearcoat coating compositions are known in the state of the art. The cured multilayer coating preferably comprises at least one pigmented coating layer (e.g. basecoat layer) and optionally at least one clearcoat and/or tinted clearcoat layer.

Preferred plastic substrates are basically substrates comprising or consisting of (i) polar plastics, such as polycarbonate, polyamide, polystyrene, styrene copolymers, polyesters, polyphenylene oxides and blends of these plastics, (ii) synthetic resins such as polyurethane RIM, SMC, BMC and (iii) polyolefin substrates of the polyethylene and polypropylene type with a high rubber content, such as PP-EPDM, and surface-activated polyolefin substrates. The plastics may furthermore be fiber- reinforced, in particular using carbon fibers and/or metal fibers.

Preferably substrates according to the method of the present invention are (i) vehicles, including but not limited to automobiles, trucks, agricultural machines, ships, airplanes, motorcycles, etc., as well as parts of such vehicles; (ii) furniture surfaces, such as kitchen surfaces; (iii) everyday items, such as sportswear, helmets, etc..

First coating layer (CL-1):

The first coating layer (CL-1) of the inventive peelable coating layer is formed on the surface of the substrate (S) by applying a first coating composition (C-1 ) to at least part of the surface of said substrate (S). The first coating composition (C-1) comprises at least one polyvinylaromatic-polydiene block copolymer (a-1), at least one rubber copolymer being different from copolymer (a-1 ) (a-2), at least one alicyclic hydrocarbon (a-3) and at least one organic solvent (a-4).

Polyvinylaromatic-polydiene block copolymer (a-1):

The at least one polyvinylaromatic-polydiene block copolymer (a-1) preferably has a total apparent molecular weight in the range of from 45 to 160 kg/mole, more preferably from 50 to 100 kg/mole, very preferably from 55 to 90 kg/mole, as determined by GPC using polystyrene as internal standards according to ASTM D 5296-19. As used herein, unless otherwise noted, the term “apparent molecular weight” refers to the molecular weight of polymers measured using GPC calibrated with polystyrene at the peak of the GPC trace (also known as styrene equivalent molecular weight). The apparent molecular weight may be converted to true molecular weight when the styrene content of the polymer and the vinyl content of the diene segments are known.

It will be appreciated that, depending on the coupling efficiency of the applied coupling agent, a certain amount of non-coupled terminated diblock copolymer will be present in the finally obtained block copolymer. It is, however, preferred, if the amount of non- coupled diblock copolymer (i.e. the diblock content) is rather low, preferably from 0 to 20 wt.%, preferably of 0 to 5 wt.%, based in each case on the total weight of the polyvinylaromatic-polydiene block copolymer (a-1).

The component (a-1) is preferably selected from block copolymers that comprise at least two blocks A of polymerized monovinyl arene, thus giving a glossy (resinous) monovinyl aromatic segment, and a selectively hydrogenated block B composed of - prior to hydrogenation - polymerized conjugated diene, which provides an amorphous elastomeric segment. The term “selectively hydrogenated” refers to the selective hydrogenation of double bonds the block B, i.e. the aromatic double bonds present in block A have not been hydrogenated or only in a degree of at most 5%. Preferably, at least 90% of the double bonds in elastomeric block B, preferably at least 95% of the double bonds in elastomeric block B, very preferably 98% of the double bonds in elastomeric block B are selectively hydrogenated. The hydrogenation of these block copolymers may be carried out by a variety of well- established processes including hydrogenation in the presence of such catalysts as Raney Nickel, noble metals such as platinum and palladium and soluble transition metal catalysts. Suitable hydrogenation processes which can be used are ones wherein the diene-containing polymer or copolymer is dissolved in an inert hydrocarbon diluent such as cyclohexane and hydrogenated by reaction with hydrogen in the present of a soluble hydrogenation catalyst. Such processes are disclosed in US Patent Nos. 3,113,986 , 3,700,633 , 4,226,952 and Reissues 27,145 . The polymers are hydrogenated in such a manner as to produce hydrogenated polymers having a residual unsaturation content in polydiene blocks of less than 5 percent by weight, preferably less than 1 %wt and more preferably as close to 0 percent as possible, of their original unsaturation content prior to hydrogenation. A titanium catalyst such as disclosed in US Patent 5,039,755 , may also be used in the hydrogenation process. The hydrogenation degree can be analyzed using the Nuclear Magnetic Resonance (NMR) method.

The block copolymer may correspond to the general formula (I) or (II) or (III), in particular to the general formula (I) or (II)

ABA (I)

(AB)nX (II)

ABA”B” (III) in which

A and A” represent a poly(monovinyl arene) block, wherein the blocks A and A” are different and the blocks A are larger than the blocks A”,

B and B” represent a selectively hydrogenated poly(conjugated diene(s)) or poly(diene(s)) block, wherein the blocks B are larger than the blocks B”, n is an integer ³2, and X is the remainder of a coupling agent.

Block copolymers of general formula (I) are linear, while block copolymer of general formula (II) are radial. The linear and radial block copolymers may also comprise a multitude of alternating A and B blocks. Suitable monovinyl aromatic monomers for preparing block A and A” contain from 8 to 30 carbon atoms and be a single monomer or of mixtures thereof, including styrene, C1-C4 alkylstyrene, C1-C4 dialkylstyrene, vinyl toluene, vinylnaphthalene or mixtures thereof, in particular styrene, a-methylstyrene, o-methylstyrene, p-methylstyrene, 1,3- dimethylstyrene, p-tert.-butylstyrene or mixtures thereof. Most preferably styrene is used as monovinyl aromatic monomer to prepare block A and A”.

Block A preferably represents substantially pure poly(styrene) block(s), each having a true molecular weight in the range of 5 to 15 kg/mole, determined by GPC using polystyrene as internal standards according to ASTM D 5296-97. The term “substantially pure” refers to blocks A or A” having a styrene content of more than 75 % by weight, preferably of more than 90 % by weight, very preferably of more than 95 % by weight, based in each case on the total weight of block A or A”.

The total monovinyl aromatic content of the block copolymer (e.g., poly(monovinyl arene) block A or A”) is generally within the range of from 10 to 50 weight percent, preferably from 18 to 35 weight percent, based in each case on the total weight of the polyvinylaromatic-polydiene block copolymer (a-1).

The poly(conjugated diene(s)) blocks B and B” are preferably formed by polymerizing conjugated diene monomers containing from 4 to 8 carbon atoms. Suitable conjugated diene monomers include 1,3-butadiene, 2-methyl-1 ,3-butadiene (isoprene), 2,3- dimethyl-1 ,3-butadiene or mixtures thereof, preferably from 1 ,3-butadiene or isoprene. Most preferably 1 ,3-butadiene is used as conjugated diene monomer to prepare blocks B or B”.

The anionic polymerization of the butadiene is typically controlled with structure modifiers such as diethyl ether or ethyl glyme (1 ,2-diethoxyethane), to obtain the desired amount of 1.2-addition. As described in U.S. Pat. No. Re. 27,145, the level of 1,2-addition of a butadiene polymer or copolymer can greatly affect elastomeric properties after hydrogenation. The result of polymerizing 1,3-butadiene via a 1,2- addition mechanism is a monosubstituted olefin group pendant to the polymer backbone, a vinyl group. In the case of anionic polymerization of isoprene, insertion of the isoprene via a 3,4-addition mechanism affords a geminal dialkyl C=C moiety pendant to the polymer backbone. The effects of 3,4-addition polymerization of isoprene on the final properties of the block copolymer will be similar to those from 1 ,2- addition of butadiene. When referring to the use of butadiene as the conjugated diene monomer, it is preferred that about 10 to 80 mol percent of the condensed butadiene units in the blocks B and B” have a 1 ,2-addition configuration. Preferably, from about 30 to about 80 mol percent of the condensed butadiene units should have 1 ,2-addition configuration. When referring to the use of isoprene as the conjugated diene, it is preferred that about 5 to 80 mol percent of the condensed isoprene units in the block have 3,4-addition configuration. Control of the addition mechanism can be done by utilizing an organic polar compound such as ether, including cyclic ethers, polyethers and thioethers or an amine including secondary and tertiary amines. Both non chelating and chelating polar compounds can be used. Among the polar compounds which may be added in accordance with the one aspect of this invention are dimethyl ether, diethyl ether, ethyl methyl ether, ethyl propyl ether, dioxane, dibenzyl ether, diphenyl ether, dimethyl sulfide, diethyl sulfide, tetramethylene oxide (tetrahydrofuran), tripropyl amine, tributyl amine, trimethyl amine, triethyl amine, pyridine and quinoline and mixtures thereof. The amount of polar modifier is controlled in order to obtain the desired vinyl content in the conjugated diene block.

The total content of the poly(conjugated diene(s)) or poly(diene(s)) blocks B and B” is generally from 50 to 90 weight percent, preferably from 65 to 82 weight percent, based on the total weight of the polyvinylaromatic-polydiene block copolymer (a-1 ).

Suitable block copolymers (a-1) can be prepared as described in US 3,231,635 and US 5,194,530 by sequential polymerization of the respective batches and selective hydrogenation of B or B" blocks in the obtained block copolymer, or by initial preparation of e.g. a living diblock AB precursor which can be coupled with a coupling agent into A-B-A or (AB) _n X block copolymers, which can be subsequently selectively hydrogenated.

In the sequential polymerization the monovinyl aromatic monomer is polymerized in a first step to form a monovinyl aromatic hydrocarbon block, followed by the addition of a batch of conjugated diene and completion of the polymerization to form a block copolymer A-B-Z, wherein Z is an active anionic polymerization site, such as Li ⁺ , where after a batch of monovinyl aromatic hydrocarbon monomer is added and the polymerization is continued until completion. The living block copolymer obtained is terminated by addition of a proton donating agent and preferably water or an alcohol, more preferably methanol. In general, the monomer or monomers are contacted with an organoalkali metal compound in a suitable solvent at a temperature within the range from -150°C to 300°C, preferably at a temperature within the range from 0°C to 100°C. Particularly effective polymerization initiators are organolithium compounds having the general formula (IV)

RLi (IV) wherein

R is an aliphatic, cycloaliphatic, alkyl-substituted cycloaliphatic, aromatic or alkyl- substituted aromatic hydrocarbon radical having from 1 to 20 carbon atoms of which sec. butyl is preferred.

Suitable solvents include aliphatic, cycloaliphatic, alkyl-substituted cycloaliphatic, aromatic and alkyl-substituted aromatic hydrocarbons, ethers and mixtures thereof. Suitable solvents, then, include aliphatic hydrocarbons such as butane, pentane, hexane and heptane, cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane and cycloheptane, alkyl-substituted cycloaliphatic hydrocarbons such as methylcyclohexane and methylcycloheptane, aromatic hydrocarbons such as benzene and the alkyl-substituted hydrocarbons such as toluene and xylene, and ethers such as tetrahydrofuran, diethylether and di-n-butyl ether. Preferred solvents are cyclopentane or cyclohexane.

The A-B-A block copolymers and (AB) _n X block copolymers can be manufactured by coupling of an initially prepared living block copolymer A-B-Z with a coupling agent. As examples of the coupling agent may be mentioned tin coupling agents such as tin dichloride, monomethyltin dichloride, dimethyltin dichloride, monoethyltin dichloride, diethyltin dichloride, methyltin trichloride, monobutyltin dichloride, dibutyltin dibromide, monohexyltin dichloride and tin tetrachloride; halogenated silicon coupling agents such as dichlorosilane, monomethyldichlorosilane, dimethyldichlorosilane, diethyldichlorosilane, monobutyldichlorosilane, dibutyldichlorosilane, monohexyldichlorosilane, dihexyldichlorosilane, dibromosilane, monomethyldibromosilane, dimethyldibromosilane, silicon tetrachloride and silicon tetrabromide; alkoxysilanes such as tetramethoxysilane; divinyl aromatic compounds such as divinylbenzene divinyl naphthalene; halogenated alkanes such as dichloroethane, dibromoethane, methylene chloride dibromomethane, dichloropropane, dibromopropane, chloroform, trichloroethane, trichloropropane and tribromopropane; halogenated aromatic compounds such as dibromobenzene; epoxy compounds such as the diglycidyl ether of bisphenol-A (e.g. EPON 825, a trademark), and other coupling agents such as benzoic esters, CO2, 2-chloroprene and 1 chloro- 1, 3-butadiene. Of these EPON 825 diglycidyl ether, dibromobenzene, tetramethoxysilane and dimethyldichlorosilane are preferred.

The block copolymer (a-1) may be prepared by any method known in the art including the well-known full sequential polymerization method, optionally in combination with re-initiation, and the coupling method, as illustrated in e.g. US 3,231 ,635 A, US 3,251,905 A, US 3,390,207 A, US 3,598,887 A, US 4,219,627 A, EP 0413294 A2 , EP 03876671 B1 , EP 0636654 A1 and WO 94/22931 A1.

Block copolymers that may be used as component (a-1) are commercially available under the tradenames KRATON® G1650, G1652 and MD 1648 from Kraton Corporation.

Rubber copolymer (a-2)

The rubber copolymer (a-2) is different from the block copolymer (a-1 ) and is preferably is selected from butene home or copolymers, preferably from butene copolymers, very preferably from isobutylene-butene copolymers.

Suitable rubber copolymers (a-2) have a number average molecular weight of 300 to 5,000 g/mole, preferably of 500 to 3,000 g/mole, as determined by GPC using polystyrene as internal standards according to ASTM D 5296-19, and a viscosity at 100 °C of 11 to 45,000 cSt, as determined according to ASTM D 445-21. Such polybutenes are essentially water white, resistant to oxidation by light and heat, nondrying and thermally decompose without residue at a temperature above about 275° C. Such polybutenes may be obtained by the polymerization of a refinery butenes stream in the presence of a Friedel-Crafts-type catalyst. The refinery butenes stream, often identified as the "C4 " or "B-B" (Butanes-Butenes) olefin stream from petrochemical cracking units, is a convenient source of isobutylene, 1 -butene, and cis- and trans-2-butene. The polybutenes comprise isobutylene-butene copolymers made up of high molecular weight mono-olefins (95 to 100%) and isoparaffins. Rubber copolymers that may be used as component (a-2) are commercially available. Typical examples of suitable rubber copolymers are Indopol L-8, Indopol L-14, Indopol H-8, Indopol H-14, Indopol H-15, Indopol H-25, Indopol H-50, Indopol H-100, Indopol H- 300, Indopol H-1200, Indopol H-1500, Indopol H-1900 and Indopol H-2100 provided by Amoco Chemical Company.

Alicyclic hydrocarbon resin (a-3):

Examples of suitable alicyclic hydrocarbon resin (a-3) include resins produced by polymerizing unsaturated monomers present in at least one petroleum fraction, resins produced by polymerizing unsaturated cyclic monomers, resins produced by hydrogenating substantially all residual ethylenic and aromatic unsaturation in an aromatic hydrocarbon resin, resins produced by hydrogenating substantially all residual ethylenic and aromatic unsaturation in an aliphatic hydrocarbon-aromatic hydrocarbon copolymer resin and mixtures thereof. The term “substantially all” is meant here to include a residual ethylenic and/or aromatic content of less than 10 % by weight, preferably less than 7 % by weight, very preferably less than 5 % by weight, based on the total weight of the respective resin. The residual ethylenic and aromatic content can, for example, be determined by ¹ H-NMR techniques.

The petroleum fraction may be selected from at least one Cs to C20 petroleum fraction, in particular from a Cs and/or C9 petroleum fraction. Alicyclic hydrocarbon resins produced from a Cs and C9 petroleum fraction are, for example, produced by polymerization of monomers comprising at least one unsaturated aromatic Cs, C9, and/or C10 species boiling in the range from about 100°C to about 300°C at atmospheric pressure and at least one monomer comprising Cs and/or C6 olefin species boiling in the range from about 20°C to about 200°C at atmospheric pressure. In one embodiment, Cs and/or C6 species include paraffins, olefins, and diolefins also referred to as “Cs monomers or Cs petroleum fraction.” These monomer streams are comprised of cationically polymerizable monomers such as 1 ,3-pentadiene which is the primary reactive component along with cyclopentene, pentene, 2-methyl-2-butene, 2-methyl-2-pentene, cyclopentadiene, and dicyclopentadiene. In one embodiment, unsaturated aromatic Ce, C9, and/or C10 monomers are derived from petroleum distillates resulting from naphtha cracking and are referred to as “C9 monomers.” These monomer streams are comprised of cationically polymerizable monomers such as styrene, alpha methyl styrene, beta-methyl styrene, vinyl toluene, indene, dicyclopentadiene, divinylbenzene, and other alkyl substituted derivatives of these components. The cationic polymerization is in some instances catalyzed using Friedel- Crafts polymerization catalysts such as Lewis acids (e.g., boron trifluoride (BF3), complexes of boron trifluoride, aluminum trichloride (AICL), and alkyl aluminum chlorides). In addition to the reactive components, non-polymerizable components include, aromatic hydrocarbons such as xylene, ethyl benzene, cumene, ethyl toluene, indane, methylindane, naphthalene and other similar specifies. The non-polymerizable components of the feed stream are in some embodiments incorporated into the thermoplastic resins via alkylation reactions.

Exemplary commercial low molecular weight hydrocarbon resins may include the following: hydrocarbon resins available from Eastman Chemical under the trademark Piccotac®; the fully hydrogenated alicyclic hydrocarbon resin based on C9 monomers available from Arakawa Chemical Inc. under the trademark Arkon® and sold, depending on softening point, as Arkon® P140, P125, P115, P100, P90, P70 or the partially hydrogenated hydrocarbon resins sold as Arkon® M135, M115, M100 and M90; the fully or partially hydrogenated hydrocarbon resin available from Eastman Chemical under the tradename Regalite® and sold, depending on softening point, as Regalite® R1100, S1100, R1125, R1090 and R1010, or the partially hydrogenated resins sold as Regalite® R7100, R9100, S5100 and S7125; the hydrocarbon resins available from Exxon Chemical under the trade Escorez®, sold as the Escorez® 1000, 2000 and 5000 series, based on C5 to C9 feedstock and mixes thereof, or the hydrocarbon resins sold as the Escorez® 5300, 5400, and 5600 series based on cyclic and C9 monomers, optionally hydrogenated.

Suitable unsaturated cyclic monomers include cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, methyl cyclopentadiene, dicyclopentadiene, methylcyclopentadiene dimer or mixtures thereof. In some embodiments, the hydrocarbon resin has a softening point of 70 to 150 °C, preferably 80 to 140 °C, as determined according to ASTM E28-18.

The first coating composition (C-1) preferably comprises compounds (a-1), (a-2) and (a-3) in a total amount of 5 to 30 % by weight, preferably 10 to 25 % by weight, very preferably 15 to 18 % by weight, based in each case on the total weight of the coating composition (C-1 ). Use of compounds (a-1 ) to (a-3) in the aforementioned total weight results on the one hand in a sufficient adhesion of the formed coating layer (CL-1) on the substrate and a sufficient interlayer adhesion to coating layer (CL-2) and, on the other hand, allows to substantially fully remove the coating layer (CL-1) from the underlying substrate by peeling without damaging the substrate.

Organic solvent (a-4):

Suitable organic solvents include (i) aliphatic and/or aromatic hydrocarbons, such as toluene, xylene, solvent naphtha, Solvesso 100 or Hydrosol® (from APAL), ethylbenzene, naphthalene; (ii) ketones, such as acetone, methyl ethyl ketone or methyl amyl ketone; (iii) esters, such as ethyl acetate, butyl acetate, pentyl acetate or ethyl ethoxypropionate, 2-methoxy-1-methylethyl acetate (iv) ethers, such as diethylene glycol monophenyl ether; and (v) mixtures thereof, preferably aromatic hydrocarbons and ketones, in particular a mixture of toluene, xylene, solvent naphtha and acetone.

The coating composition (C-1 ) is preferably a solvent-based coating composition. Such solvent-based coating compositions preferably comprises a total amount of water and/or protic solvents of less than 10 wt.-%, preferably less than 5 wt.-%, more preferably less than 1 wt.-%, very preferably 0 wt.-%, based in each case on the total weight of the coating composition. The organic solvent (a-4) is preferably present in a total amount of 60 to 95 % by weight, more preferably 70 to 90 % by weight, very preferably 75 to 85 % by weight, based in each case on the total weight of the coating composition (C-1).

Fumed silica (a-5)

The coating composition (C-1) may further comprise at least one fumed silica (a-5), in particular at least one hydrophobic fumed silica. Suitable compounds for preparing hydrophobic fumed silica include dimethyldichlorosilane. Such hydrophobic fumed silica is commercially available, for example as AEROSIL® R 972 and R 974 from Evonik Industries AG.

The fumed silica (a-5) may be present in total amount of 0.1 to 5 % by weight, preferably of 0.5 to 3 % by weight, very preferably of 1 to 2 % by weight, based in each case on the total weight of the coating composition (C 1 ).

Further ingredients (a-6)

The coating composition (C-1) may, apart from mandatory components (a-1) to (a-4) and optional component (a-5) comprise at least one additive (a-6). Suitable additives (a-6) include (i) UV absorbers; (ii) light stabilizers, such as HALS compounds; (iii) levelling agents; (iv) antioxidants; (v) catalysts; (vi) surfactants; and (vii) mixtures thereof.

The at least one additive (a-6) is preferably present a total amount of 0.1 to 5 % by weight, more preferably 0.5 to 3 % by weight, very preferably 1 to 2 % by weight, based in each case on the total weight of the coating composition (C-1).

Second coating layer (CL-2):

The second coating layer (CL-2) of the inventive peelable coating layer is formed on the first coating layer (CL-1) by applying a second coating composition (C-2) to at least part of the first coating layer (CL-1). The second coating composition (C-2) comprises at least one pigment (b-1) and at least one binder (b-2).

Pigment (b-1):

The at least one pigment (b-1) may be selected from color pigments and/or effect pigments. The term “color pigment” or “coloring pigment” refers to pigments producing an optical effect based on selective light absorption in conjunction with light scattering. Examples of color pigments include inorganic and organic color pigments. The term “inorganic color pigment” refers to natural and synthetically produced pigments based on inorganic compounds and includes white pigments, inorganic colored pigments and black pigments. The term “organic color pigment” refers to coloring agents which are practically insoluble in the application medium and includes azo pigments and polycyclic pigments, i.e. organic non-azo pigments characterized by at least one aromatic and/or heteroaromatic ring system. In contrast, the term “effect pigment” or “visual effect pigment” refers to pigments producing an optical effect, such as a color or lightness effect, based primarily on light reflection, in particular on angle dependent light reflection. Examples of effect pigments include luster pigments, such as metal effect pigments, pearlescent pigments and interference pigments, flaky graphene, flaky iron oxide and micronized titanium dioxide.

Suitable color pigments include monoazopigments, such as C.l. Pigment Brown 25, C.l. Pigment Orange 5, 36 and 67, C.l. Pigment Orange 5, 36 and 67, C.l. Pigment Red 3, 48:2, 48:3, 48:4, 52:2, 63, 112 and 170, and C.l. Pigment Yellow 3, 74, 151 and 183; disazopigments, such as C.l. Pigment Red 144, 166:214 and 242 C.l. Pigment Red 144, 166:214 and 242, 15 and also C.l. Pigment Yellow 83; anthraquinone pigments, such as C.l. Pigment Yellow 147 and 177, and also C.l. Pigment Violet 31; benzimidazole pigments, such as C.l. Pigment Orange 64; quinacridone pigments, such as C.l. Pigment Orange 48 and 49, C.l. Pigment Red 122, 202 and 206, and C.l. Pigment Violet 19; quinophthalone pigments, such as C.l. Pigment Yellow 138; diketopyrrolopyrrole pigments, such as C.l. Pigment Orange 71 and 73, and C.l. Pigment Red 254, 255, 264 and 270; dioxazine pigments, such as C.l. Pigment Violet 23 and 37; indanthrone pigments, such as C.l. Pigment Blue 60; isoindoline pigments, such as C.l. Pigment Yellow 139 and 185; isoindolinone pigments, such as C.l. Pigment Orange 61 and also C.l. Pigment Yellow 109 and 110; metal complex pigments, such as C.l. Pigment Yellow 153; perinone pigments, such as C.l. Pigment Orange 43; perylene pigments, such as C.l. Pigment Black 32, C.l. Pigment Red 149, 178 and 179 and C.l. Pigment Violet 29; phthalocyanine pigments, such as C.l. Pigment Violet 29, C.l. Pigment Blue 15, 15:1 , 15:2, 15:3, 15:4, 15:6 and 16, and C.l. Pigment Green 7 and 36; aniline black, 30 such as C.l. Pigment Black 1; azomethine pigments; white pigments, such as titanium dioxide (C.l. Pigment White 6), zinc white, pigmentary zinc oxide, zinc sulfide, lithopone; black pigments, such as black iron oxide (C.l. Pigment Black 11), iron manganese black, spinell black (C.l. Pigment Black 27), carbon black (C.l. Pigment Black 7); chromatic pigments, such as ultramarine green, ultramarine blue, manganese blue, ultramarine violet, manganese violet, red iron oxide (C.l. Pigment Red 101), molybdate red (C.l. Pigment Red 104), ultramarine red, brown iron oxide, mixed brown, spinell phases and corundum phases (C.l. Pigment Brown 24, 29 and 31), yellow iron oxide (C.l. Pigment Yellow 42), bismuth vanadate (C.l. Pigment Yellow 184); silicon dioxide; ground quartz; aluminum oxide; aluminum hydroxide; natural micas; natural and precipitated chalk; barium sulfate; and mixtures thereof.

Suitable effect pigments include platelet-shaped metallic effect pigments such as platelet-shaped aluminum pigments, gold bronzes, oxidized bronzes and/or 30 iron oxide-aluminum pigments, pearlescent pigments and/or metal oxide-mica pigments and/or other effect pigments such as platelet-shaped graphite, platelet-shaped iron oxide, multilayer effect pigments composed of PVD films and/or liquid crystal polymer pigments and mixtures thereof.

Binder (b-2)

The second coating composition (C-2) comprises at least one binder (b-2). Said binder (b-2) may be selected from (i) poly(meth)acrylates, more particularly hydroxy- functional and/or carboxylate-functional and/or amine-functional poly(meth)acrylates, (ii) polyurethanes, more particularly hydroxy-functional and/or carboxylate-functional and/or amine-functional polyurethanes, (iii) polyesters, more particularly polyester polyols and polycarbonate polyols, (iv) polyethers, more particularly polyether polyols, (v) copolymers of the stated polymers, and (vi) mixtures thereof, preferably from hydroxy-functional poly(meth)acrylates, hydroxy-functional polyurethanes, hydroxy- functional polyesters, hydroxy-functional polyethers and copolymers of said polymers.

According to a first alternative, the second coating composition (C-2) is an aqueous coating composition prepared from a mixing system (M1) comprising: at least one aqueous pigment paste comprising at least one color or effect pigment and having a VOC value of less than or equal to 250 g/L, and at least one pigment-free component comprising an acrylate-based microgel dispersion having a glass transition temperature T _g of 50 to 60°C and having a VOC value of less than or equal to 250 g/L.

The mixer system (M1) may further comprise at least one rheology modifying component which controls the rheology of the coating composition (C-2) and which comprises at least one thickener and 90 to 98 wt.% of water, based on the total weight of this component. The mixer system (M1) may further comprise at least one crosslinker component comprising at least one crosslinking agent. A suitable mixer system (M1) is, for example, disclosed in published patent applications WO 2021/018595 A1 and WO 2021/018594 A1 and is commercially available under the brand names Glasurit® 100 Line and R-M® AGILIS from BASF Coatings GmbH.

According to a second alternative, the second coating composition (C-2) is prepared from a mixing system (M2) comprising: at least one pigment paste comprising at least one color and/or effect pigment and having a water content of less than 5 % by weight, based on the total weight of the pigment paste, and at least one aqueous pigment-free component.

The mixer system (M1) may further comprise at least one rheology modifying component which controls the rheology of the coating composition (C-2) and which comprises at least one thickener and 90 to 98 wt.% of water, based on the total weight of this component. A suitable mixer system (M2) is, for example, disclosed in published patent application DE 4110520 A1 and is commercially available under the brand name Glasurit® Line 90 and from BASF Coatings GmbH.

The coating composition (C-2) is obtained from the mixer system (M1) or (M2) by mixing the respective pigment paste, the pigment-free component and optionally the rheology modifying component and/or optionally the crosslinker component. In case of the mixer system (M1), the resulting coating composition (C-2) has a VOC content of 0 to 250 g/L while in case of mixer system (M2), the resulting coating composition (C- 2) has a VOC content of 300 to 450 g/L. The mixer systems (M1) and (M2) are designed for use in refinish processes which require low temperatures for curing and thus can be used on manufactured automotive without destroying the automotive during curing of the coating composition (C-2). Use mixer systems to prepare the colored coating composition (C-2) allows to obtain peelable coating systems in all colors currently available in the automotive sector. Moreover, specific colors can be designed by mixing the pigments pastes of the systems in defined rations, thus allowing to create individual colors, such as company colors or the like, thus allowing to personalize the substrate in any desired color. Third coating layer (CL-2):

The third coating layer (CL-3) of the inventive peelable coating layer is formed on the second coating layer (CL-2) by applying a third coating composition (C-3) to at least part of the second coating layer (CL-3). In one example, the third coating composition (C-3) is formulated as tinted clearcoat composition which, when applied to a substrate, are neither completely transparent and colorless as a clear coating nor completely opaque as a typical pigmented coating. A tinted clear coating is therefore transparent and colored or semi-transparent and colored. The color can be achieved by adding at least one color and/or effect pigment previously described in a total amount of 0.1 to 10 wt.-%, preferably 1 to 4 wt.-%, based on the total weight of the coating composition (C-3). In another example, the third coating composition (C-3) is formulated as a clearcoat composition.

The clearcoat material (C-3) may in principle be any transparent coating composition known to the person skilled in the art in this context. This includes aqueous or solvent borne transparent coating compositions as well as powder clearcoat materials. Suitable clearcoat materials are water-borne, solvent-borne and powder clearcoat materials, such as, for example, described in DE 34 12 534, DE 3609519, DE 3731 652, and DE 3823005.

The tinted clearcoat and/or clearcoat materials may be formulated as one-component or two-component or multicomponent coating compositions. In case of one-component coating compositions, crosslinking reactions during storage need to be avoided, for example by using blocked crosslinking agents which are only reactive at higher temperatures. Two-component coating compositions comprise the reactive components, i.e. binder and crosslinker, in separate containers. The components of containers 1 and 2 are then mixed prior to use, preferably shortly before application of the mixed coating composition to the substrate. Preference is given to solvent-based multi-component clearcoat and/or tinted clearcoat compositions.

Inventive method:

The inventive method for forming a peelable coating system onto at least part of a surface of a substrate involves the application of the three coating compositions (C-1 ), (C-2) and (C-3) consecutively over the object to be coated in the manner described below. The peelable coating system is formed from the first coating layer (CL-1), the second coating layer (CL-2) and the third coating layer (CL-3) and an adhesive strength between the first coating layer (CL-1), the second coating layer (CL-2) and the third coating layer (CL-3) is greater than an adhesive strength between the first coating layer (CL-1) and the surface of the substrate (S).

The at least three different coating compositions that are used in the method of the present invention include: the first coating composition (C-1) to provide a peelable base; the second coating composition (C-2) comprising pigment(s) is used to obtain the desired color of the peelable coating system; and a tinted clearcoat and/or tinted clearcoat composition (C-3).

Step (i)

Step (i) of the inventive method comprises applying the first coating composition (C-1 ) to at least part of a surface of the substrate and optionally drying the applied first coating composition (C-1) to form a first coating film (CF-1). The first coating composition (C-1) used in step (i) corresponds to the first coating composition (C-1) described previously in relation to the inventive peelable coating system.

The coating composition (C-1) can be applied by methods known to those skilled in the art for application of liquid coating compositions, for example by dipping, bar coating, spraying, rolling or the like. Preference is given to employing spray application methods, for example compressed air spraying (pneumatic application), airless spraying, high-speed rotation, electrostatic spray application (ESTA), optionally in association with hot-spray application, for example hot-air spraying. Most preferably, the basecoat material(s) is/are applied by means of compressed air spraying.

After application, the applied coating composition (C-1) is dried, for example, at 15 to 30°C, preferably at 18 to 25°C, for 5 to 25 minutes, preferably for 10 to 15 minutes. The applied coating composition (C-1) is not cured in step (i), i.e. it is preferably not exposed to temperatures of more than 50 °C for a period of longer than 1 min, and especially preferably are not exposed to temperatures of more than 50 °C at all. The application of the coating composition (C-1) is preferably effected in such a way that the first coating layer (CL-1), after the curing in step (ii), has a dry film thickness of 50 to 500 pm, preferably of 80 to 300 pm, very preferably of 90 to 150 pm.

In order to achieve the aforementioned film thickness, it may be beneficial if step (i) is repeated at least once, preferably at least twice, very preferably at least four times. In case step (i) is repeated at least once, the term “coating film” refers to the multilayer film obtained after the last repetition of step (i).

Step (ii)

In step (ii) of the inventive method, the first coating film (CF-1) formed in step (i) is cured to form a first coating layer (CL-1 ).

The curing is preferably performed at 15 to 30°C, preferably at 18 to 25°C, for 30 to 180 minutes, preferably for 50 to 70 minutes.

Step (Hi):

In step (iii), the second coating composition (C-2) is applied on at least part of the first coating layer (CL-1) and optionally drying to form a second coating film (CF-2). The second coating composition (C-2) used in step (iii) corresponds to the second coating composition (C-2) described previously in relation to the inventive peelable coating system.

Application of second coating composition (C-2) can be performed using the methods previously described in relation to step (i) directly after production of the coating material (C-2), for example from mixer system (M1) or (M2) previously described. It may be beneficial if no flashing takes place between multiple applications of the coating composition (C-2). Multiple applications may be required to achieve the desired dry film thickness after curing in step (v) described below.

It may be beneficial in terms of overall visual appearance to dry the applied second coating composition (C-2) at 15 to 30°C for a duration of 1 to 10 minutes, preferably of 3 to 8 minutes, prior to performing step (iii). The application of the coating composition (C-2) is preferably performed in such a way that the second coating layer (CL-2), after the curing in step (v), has a dry film thickness of 5 to 25 pm.

Step (iv):

In step (iv), the third coating composition (C-3) is applied on at least part of the second coating film (CF-2) to form a third coating film (CF-3). The third coating composition (C-3) used in step (iv) corresponds to the third coating composition (C-3) described previously in relation to the inventive peelable coating system.

Application of third coating composition (C-3) can be performed using the methods previously described in relation to step (i).

The application of the coating composition (C-3) is preferably performed in such a way that the third coating layer (CL-3), after the curing in step (v), has a dry film thickness of 30 to 70 pm. In case a tinted clearcoat and a clearcoat composition are applied, the dry film thickness refers to the dry film thickness of the tinted clearcoat and the clearcoat layer.

Step (v):

In step (v) of the inventive method, the second coating film (CF-2) and the third coating film (CF-3) are jointly cured to form a second coating layer (CL-2) and a third coating layer (CL-3),

The joint curing is preferably performed at 30 °C to less than 100°C, preferably at 40 °C to less than 80°C, for a duration of 5 to 40 minutes.

What has been said about the inventive peelable coating system applies mutatis mutandis with respect to further preferred embodiments of the inventive method.

Inventive coated substrate:

After the end of the method of the invention, the result is a coated object of the invention. The coated object of the present invention has a good overall visual appearance irrespective of the pigmented coating composition used to prepare the coated substrate. Despite the good mechanical properties including the good adhesion to the underlying substrate as well as the good interlayer adhesion, peelable coating system can be removed without any residues and without damaging the underlying substrate.

What has been said about the inventive peelable coating system and the inventive method applies mutatis mutandis with respect to further preferred embodiments of the inventive coated substrates.

The invention is described in particular by the following embodiments:

1. A peelable coating system comprising

(a) a first coating layer (CL-1) being prepared by applying a first coating composition (C-1) to at least part of a surface of a substrate (S), said first coating composition (C-1) comprising

(a-1 ) at least one polyvinylaromatic-polydiene block copolymer,

(a-2) at least one rubber copolymer being different from copolymer (a-1 ), (a-3) at least one alicyclic hydrocarbon and (a-4) at least one organic solvent;

(b) a second coating layer (CL-2) being prepared by applying a second coating composition (C-2) to the first coating layer (CL-1), said second coating composition (C-2) comprising at least one pigment (b-1) and at least one binder (b-2); and

(c) a tinted clearcoat and/or a clearcoat layer (CL-3) being prepared by applying a tinted clearcoat and/or a clearcoat coating composition (C-3) to the second coating layer (CL-2); wherein the first coating layer (CL-1 ), the second coating layer (CL-2) and the third coating layer (CL-3) form a peelable coating, wherein an adhesive strength between the first coating layer (CL-1 ), the second coating layer (CL-2) and the third coating layer (CL-3) is greater than an adhesive strength between the first coating layer (CL-1 ) and the surface of the substrate (S).

2. The peelable coating system according to clause 1 , wherein the substrate (S) is selected from metallic substrates optionally coated with at least one cured coating layer, plastic substrates optionally coated with at least one cured coating layer, substrates comprising metallic and plastic components and optionally coated with at least one cured coating layer, preferably from metallic substrates coated with at least one cured coating layer, in particular from metallic substrates coated with a cured multilayer coating.

3. The peelable coating system according to clause 2, wherein the metallic substrate is selected from the group comprising or consisting of iron, aluminum, copper, zinc, magnesium and alloys thereof as well as steel.

4. The peelable coating system according to clause 2 or 3, wherein the cured multilayer coating comprises at least one pigmented coating layer and optionally at least one clearcoat and/or tinted clearcoat layer.

5. The peelable coating system according to any one of the preceding clauses, wherein the at least one polyvinylaromatic-polydiene block copolymer (a-1 ) has a total apparent molecular weight in the range of from 45 to 160 kg/mole, preferably from 50 to 100 kg/mole, very preferably from 55 to 90 kg/mole, as determined by GPC using polystyrene as internal standards according to ASTM D 5296-19.

6. The peelable coating system according to any one of the preceding clauses, wherein the at least one polyvinylaromatic-polydiene block copolymer (a-1) comprises a diblock content of 0 to 20 wt.%, preferably of 0 to 5 wt.%, based in each case on the total weight of the polyvinylaromatic-polydiene block copolymer (a-1).

7. The peelable coating system according to any one of the preceding clauses, wherein the at least one polyvinylaromatic-polydiene block copolymer (a-1) comprises at least two resinous blocks A of non-hydrogenated polymerized monovinyl arene and a selectively hydrogenated elastomeric block B, wherein said block B - prior to hydrogenation - comprises polymerized conjugated diene(s) or polymerized diene(s).

8. The peelable coating system according to clause 7, wherein at least 90% of the double bonds in elastomeric block B, preferably at least 95% of the double bonds in elastomeric block B, very preferably 98% of the double bonds in elastomeric block B are selectively hydrogenated. The peelable coating system according to any one of the preceding clauses, wherein the at least one polyvinylaromatic-polydiene block copolymer (a-1) corresponds to the general formula (I) or (II) or (III), in particular to formula (I) or

(II)

ABA (I)

(AB)nX (II)

ABA”B” (III) in which

A and A” represent a poly(monovinyl arene) block, wherein the blocks A and A” are different and the blocks A are larger than the blocks A”,

B and B” represent a selectively hydrogenated poly(conjugated diene(s)) or poly(diene(s)) block, wherein the blocks B are larger than the blocks B”, n is an integer ³2, and X is the remainder of a coupling agent. The peelable coating system according to any one of clauses 7 to 9, wherein the poly(monovinyl arene) block A and A” is formed by polymerizing monovinyl aromatic monomers selected from styrene, C1-C4 alkylstyrene, Ci- C4 dialkylstyrene, vinyl toluene, vinylnaphthalene or mixtures thereof, in particular styrene, a-methylstyrene, o-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, p-tert.-butylstyrene or mixtures thereof, most preferably styrene. The peelable coating system according to any one of clauses 7 to 10, wherein the poly(monovinyl arene) block A represents substantially pure poly(styrene) block(s), each having a molecular weight in the range of 5 to 15 kg/mole, determined by GPC using polystyrene as internal standards according to ASTM D 5296-97. The peelable coating system according to any one of clauses 7 to 11 , wherein the total content of the poly(monovinyl arene) blocks A is from 10 to 50 weight percent, preferably from 18 to 35 weight percent, based on the total weight of the polyvinylaromatic-polydiene block copolymer (a-1). 13. The peelable coating system according to any one of clauses 7 to 12, wherein the poly(conjugated diene(s)) block B is formed by polymerizing conjugated diene monomers containing from 4 to 8 carbon atoms.

14. The peelable coating system according to clause 13, wherein the conjugated diene monomer is selected from 1,3-butadiene, 2-methyl-1 ,3-butadiene (isoprene), 2,3- dimethyl-1, 3-butadiene or mixtures thereof, preferably from 1,3-butadiene or isoprene, very preferably from 1 ,3-butadiene.

15. The peelable coating system according to clause 13 or 14, wherein 5 to 80 mol percent, preferably 30 to 80 mol percent, of the polymerized conjugated diene monomers have a 1 ,2-addition configuration or a 3,4-addition configuration.

16. The peelable coating system according to any one of clauses 7 to 15, wherein the total content of the poly(conjugated diene(s)) or poly(diene(s)) block B is from 50 to 90 weight percent, preferably from 65 to 82 weight percent, based on the total weight of the polyvinylaromatic-polydiene block copolymer (a-1).

17. The peelable coating system according to any one of the preceding clauses, wherein the at least one rubber copolymer (a-2) is selected from butene home or copolymers, preferably from butene copolymers, very preferably from isobutylene- butene copolymers.

18. The peelable coating system according to any one of the preceding clauses, wherein the at least one rubber copolymer (a-2) has a number average molecular weight of 300 to 5,000 g/mole, preferably of 500 to 3,000 g/mole, as determined by GPC using polystyrene as internal standards according to ASTM D 5296-19.

19. The peelable coating system according to any one of the preceding clauses, wherein the at least one rubber copolymer (a-2) has a viscosity at 100 °C of 11 to 45,000 cSt, as determined according to ASTM D 445-21. 20. The peelable coating system according to any one of the preceding clauses, wherein the at least one alicyclic hydrocarbon resin (a-3) is selected from resins produced by polymerizing unsaturated monomers present in at least one petroleum fraction, resins produced by polymerizing unsaturated cyclic monomers, resins produced by hydrogenating substantially all residual ethylenic and aromatic unsaturation in an aromatic hydrocarbon resin, resins produced by hydrogenating substantially all residual ethylenic and aromatic unsaturation in an aliphatic hydrocarbon-aromatic hydrocarbon copolymer resin and mixtures thereof.

21. The peelable coating system according to clause 20, wherein the petroleum fraction is selected from at least one Cs to C20 petroleum fraction, in particular from a Cs and/or C9 petroleum fraction.

22. The peelable coating system according to clause 20 or 21, wherein the unsaturated cyclic monomer is selected from cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, methyl cyclopentadiene, dicyclopentadiene, methylcyclopentadiene dimer or mixtures thereof.

23. The peelable coating system according to any one of the preceding clauses, wherein the at least one alicyclic hydrocarbon resin (a-3) has a softening point of 70 to 150 °C, preferably 80 to 140 °C, as determined according to ASTM E28-18.

24. The peelable coating system according to any one of the preceding clauses, wherein the coating composition (C-1 ) comprises compounds (a-1 ), (a-2) and (a-3) in a total amount of 5 to 30 % by weight, preferably 10 to 25 % by weight, very preferably 15 to 18 % by weight, based in each case on the total weight of the coating composition (C-1).

25. The peelable coating system according to any one of the preceding clauses, wherein the organic solvent (a-4) is selected from aliphatic and/or aromatic hydrocarbons, ketones, esters, ethers, or mixtures thereof, preferably aromatic hydrocarbons and ketones, in particular a mixture of toluene, xylene, solvent naphtha and acetone. The peelable coating system according to any one of the preceding clauses, wherein the coating composition (C-1) comprises the organic solvent (a-4) in a total amount of 60 to 95 % by weight, preferably 70 to 90 % by weight, very preferably 75 to 85 % by weight, based in each case on the total weight of the coating composition (C-1). The peelable coating system according to any one of the preceding clauses, wherein the coating composition (C-1) further comprises at least one fumed silica (a-5), in particular at least one hydrophobic fumed silica. The peelable coating system according to clause 27, wherein the coating composition (C-1) comprises the at least one fumed silica (a-5) in a total amount of 0.1 to 5 % by weight, preferably 0.5 to 3 % by weight, very preferably 1 to 2 % by weight, based in each case on the total weight of the coating composition (C 1 ). The peelable coating system according to any one of the preceding clauses, wherein the coating composition (C-1 ) further comprises at least one additive (a 6) selected from the group of (i) UV absorbers; (ii) light stabilizers, such as HALS compounds; (iii) levelling agents; (iv) antioxidants; (v) catalysts; (vi) surfactants; and (vii) mixtures thereof. The peelable coating system according to clause 29, wherein the coating composition (C-1 ) comprises the at least one additive (a-6) in a total amount of 0.1 to 5 % by weight, preferably 0.5 to 3 % by weight, very preferably 1 to 2 % by weight, based in each case on the total weight of the coating composition (C-1). The peelable coating system according to any one of the preceding clauses, wherein the at least one pigment (b-1 ) is selected from color pigments and/or effect pigments. The peelable coating system according to clause 31 , wherein the color pigment is selected from monoazopigments, such as C.l. Pigment Brown 25, C.l. Pigment Orange 5, 36 and 67, C.l. Pigment Orange 5, 36 and 67, C.l. Pigment Red 3, 48:2, 48:3, 48:4, 52:2, 63, 112 and 170, and C.l. Pigment Yellow 3, 74, 151 and 183; disazopigments, such as C.l. Pigment Red 144, 166:214 and 242 C.l. Pigment Red 144, 166:214 and 242, 15 and also C.l. Pigment Yellow 83; anthraquinone pigments, such as C.l. Pigment Yellow 147 and 177, and also C.l. Pigment Violet 31; benzimidazole pigments, such as C.l. Pigment Orange 64; quinacridone pigments, such as C.l. Pigment Orange 48 and 49, C.l. Pigment Red 122, 202 and 206, and C.l. Pigment Violet 19; quinophthalone pigments, such as C.l. Pigment Yellow 138; diketopyrrolopyrrole pigments, such as C.l. Pigment Orange 71 and 73, and C.l. Pigment Red 254, 255, 264 and 270; dioxazine pigments, such as C.l. Pigment Violet 23 and 37; indanthrone pigments, such as C.l. Pigment Blue 60; isoindoline pigments, such as C.l. Pigment Yellow 139 and 185; isoindolinone pigments, such as C.l. Pigment Orange 61 and also C.l. Pigment Yellow 109 and 110; metal complex pigments, such as C.l. Pigment Yellow 153; perinone pigments, such as C.l. Pigment Orange 43; perylene pigments, such as C.l. Pigment Black 32, C.l. Pigment Red 149, 178 and 179 and C.l. Pigment Violet 29; phthalocyanine pigments, such as C.l. Pigment Violet 29, C.l. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6 and 16, and C.l. Pigment Green 7 and 36; aniline black, 30 such as C.l. Pigment Black 1; azomethine pigments; white pigments, such as titanium dioxide (C.l. Pigment White 6), zinc white, pigmentary zinc oxide, zinc sulfide, lithopone; black pigments, such as black iron oxide (C.l. Pigment Black 11 ), iron manganese black, spinell black (C.l. Pigment Black 27), carbon black (C.l. Pigment Black 7); chromatic pigments, such as ultramarine green, ultramarine blue, manganese blue, ultramarine violet, manganese violet, red iron oxide (C.l. Pigment Red 101), molybdate red (C.l. Pigment Red 104), ultramarine red, brown iron oxide, mixed brown, spinell phases and corundum phases (C.l. Pigment Brown 24, 29 and 31), yellow iron oxide (C.l. Pigment Yellow 42), bismuth vanadate (C.l. Pigment Yellow 184); silicon dioxide; ground quartz; aluminum oxide; aluminum hydroxide; natural micas; natural and precipitated chalk; barium sulfate; and mixtures thereof. The peelable coating system according to clause 31 or 32, wherein the effect pigment is selected from platelet-shaped metallic effect pigments such as platelet shaped aluminum pigments, gold bronzes, oxidized bronzes and/or 30 iron oxide- aluminum pigments, pearlescent pigments and/or metal oxide-mica pigments and/or other effect pigments such as platelet-shaped graphite, platelet-shaped iron oxide, multilayer effect pigments composed of PVD films and/or liquid crystal polymer pigments and mixtures thereof. 34. The peelable coating system according to any one of the preceding clauses, wherein the at least one binder (b-2) is selected from (i) poly(meth)acrylates, more particularly hydroxy-functional and/or carboxylate-functional and/or amine- functional poly(meth)acrylates, (ii) polyurethanes, more particularly hydroxy- functional and/or carboxylate-functional and/or amine-functional polyurethanes, (iii) polyesters, more particularly polyester polyols and polycarbonate polyols, (iv) polyethers, more particularly polyether polyols, (v) copolymers of the stated polymers, and (vi) mixtures thereof, preferably from hydroxy-functional poly(meth)acrylates, hydroxy-functional polyurethanes, hydroxy-functional polyesters, hydroxy-functional polyethers and copolymers of said polymers.

35. The peelable coating system according to any one of the preceding clauses, wherein the second coating composition (C-2) is prepared from a mixing system (M1) comprising: at least one aqueous pigment paste comprising at least one color or effect pigment and having a VOC value of less than or equal to 250 g/L, and at least one pigment-free component comprising an acrylate-based microgel dispersion having a glass transition temperature T _g of 50 to 60°C and having a VOC value of less than or equal to 250 g/L.

36. The peelable coating system according to any one of clauses 1 to 34, wherein the second coating composition (C-2) is prepared from a mixing system (M2) comprising: at least one pigment paste comprising at least one color and/or effect pigment and having a water content of less than 5 % by weight, based on the total weight of the pigment paste, and at least one aqueous pigment-free component.

37. The peelable coating system according to any one of the preceding clauses, wherein the third coating composition (C-3) is selected from solvent borne 1- component or multi-component clearcoat and/or tinted clearcoat compositions, preferably from solvent borne multi-component clearcoat and/or tinted clearcoat compositions. 38. A method for forming a peelable coating system onto at least part of a surface of a substrate, said method comprising

(i) applying the first coating composition (C-1 ) to at least part of a surface of the substrate and optionally drying the applied first coating composition (C-1) to form a first coating film (CF-1 ),

(ii) curing the formed first coating film (CF-1 ) to form a first coating layer (CL-1 ),

(iii) applying the second coating composition (C-2) on at least part of the first coating layer (CL-1) and optionally drying the applied second coating composition (C-2) to form a second coating film (CF-2),

(iv) applying the third coating composition (C-3) on at least part of the second coating film (CL-2) to form a third coating film (CF-3), and

(v) jointly curing the second coating film (CF-2) and the third coating film (CF-3) to form a second coating layer (CL-2) and a third coating layer (CL-3), wherein the first coating layer (CL-1 ), the second coating layer (CL-2) and the third coating layer (CL-3) form a peelable coating, wherein an adhesive strength between the first coating layer (CL-1 ), the second coating layer (CL-2) and the third coating layer (CL-3) is greater than an adhesive strength between the first coating layer (CL-1 ) and the surface of the substrate (S).

39. The method according to clause 38, wherein the first coating composition (C-1) is dried at 15 to 30°C, preferably at 18 to 25°C, for 5 to 25 minutes, preferably for 10 to 15 minutes.

40. The method according to clause 38 or 39, wherein step (i) is repeated at least once, preferably at least twice, very preferably at least four times.

41. The method according to any one of clauses 38 to 40, wherein the first coating film (CF-1) is cured at 15 to 30°C, preferably at 18 to 25°C, for 30 to 180 minutes, preferably for 50 to 70 minutes.

42. The method according to any one of clauses 38 to 41 , wherein the first coating layer (CL-1 ) has a dry film thickness of 50 to 500 pm, preferably of 80 to 300 pm, very preferably of 90 to 150 pm. 43. The method according to any one of clauses 38 to 42, wherein the second coating composition (C-2) is dried at 15 to 30°C for a duration of 1 to 10 minutes, preferably of 3 to 8 minutes, prior to performing step (iii). 44. The method according to any one of clauses 38 to 43, wherein the joint curing in step (v) is performed at 30 to less than 100°C, preferably at 40 to less than 80°C, for a duration of 5 to 40 minutes.

45. The method according to any one of clauses 38 to 44, wherein the second coating layer (CL-2) has a dry film thickness of 5 to 25 pm.

46. The method according to any one of clauses 38 to 45, wherein the third coating layer (CL-3) has a dry film thickness of 30 to 70 pm. 47. A coated substrate obtained by the method of any one of clauses 38 to 46.

Examples

The present invention will now be explained in greater detail through the use of working examples, but the present invention is in no way limited to these working examples. Moreover, the terms "parts", "%" and "ratio" in the examples denote "parts by mass", "mass %" and "mass ratio" respectively unless otherwise indicated.

1. Methods of determination:

1.1. Peeling behavior of the peelable coating system

The peeling behavior of the peelable coating system is determined by intentionally damaging the peelable coating system in various areas, for example by cutting, and pulling on the damaged area of the peelable coating system by hand. The peeled coating layer as well as the surface of the substrate was assessed visually. If the peelable coating system could be fully removed and the surface of the substrate is not visibly damaged, the peeling behavior of the peelable coating system is rated “OK”. If the peelable coating system could not be fully removed or the surface of the substrate is visually damaged during peeling, the peeling behavior of the peelable coating system is rated “not OK”.

1.2. Determination of residues of the peelable coating system on the surface of the substrate after removal:

The residues of peelable coating system remaining on the surface of the substrate were determined visually. If the surface of the substrate showed no visual residues after removal of the peelable coating system in comparison to the surface of the substrate before application of the peelable coating system, the rating is “No”. If the surface of the substrate showed visual residues after removal of the peelable coating system in comparison to the surface of the substrate before application of the peelable coating system, the rating is “Yes”.

1.3. Determination of mechanical stability of the peelable coating system

An automotive coated with the peelable coating system was driven for a period of 6 month in the city and on motorways. Afterwards, the peelable coating system was evaluated visually for any defects in the peelable coating systems, such as craters, blisters, detachment of coating layers/peelable coating system. If no visual defects in the peelable coating system were determined, the rating was “OK”, otherwise the rating was “not OK”.

1.4 Determination of optical properties of the peelable coating system The optical properties of the peelable coating system were determined by visually comparing a multilayer coating (MC-C) with the peelable coating system (MC-I) of the invention. Both multilayer systems were prepared using identical second and third coating compositions (i.e. basecoat and clearcoat compositions). If no visual difference in the optical appearance, i.e. color and texture, between multilayer coating (MC-C) and the peelable coating system (MC-I) or visual color/texture defects were determined, the optical properties were rated “OK”. Otherwise, the optical properties were rated “not OK”.

2. Coating compositions used to prepare the multilayer coating systems 2.1 First coating composition (C-1)

The compounds listed in Table 1 were mixed to obtain the first coating material (C-1).

Table 1: Ingredients used to prepare the first coating material (C-1)

¹⁾ the resin mixture comprises: - a polyvinylaromatic-polydiene block copolymer comprising at least two resinous blocks A of non-hydrogenated polymerized monovinyl arene and a selectively hydrogenated elastomeric block B and having a total apparent molecular weight of 55 to 90 kg/mole; the poly(monovinyl arene) blocks A are formed by polymerizing styrene, the poly(monovinyl arene) blocks A each have a molecular weight in the range of 5 to 15 kg/mole and the total content of blocks A in the block copolymer is from 18-35 weight percent based on total weight of block copolymer; block B is formed by polymerizing 1,3-butadiene

- an isobutylene-butene copolymer having a number average molecular weight of 500 to 3,000 g/mole - a poly(methylstyrene-co-indene) resin having a softening point of 80 to 140 °C,

²⁾ treated with dimethyl dichlorosilane

³⁾ mixture of UV filter (Tinuvin 328), HALS compound (Tinuvin 292), antioxidants (Irganox 1010 and pentaerythritol tris(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)), catalyst (dinonylnaphthalenesulfonic acid) and surfactant (dicoco dimethyl ammonium chloride)

2.2 Second coating composition (C-2)

A pigmented coating composition was prepared by mixing the commercially available products (all available from BASF Coatings GmbFI) in the amounts listed in Table 2 below.

Table 2: Ingredients used to prepare the second coating material (C-2)

2.3 Third coating composition (C-3)

A commercially available clearcoat composition (Glasurit® FIS clearcoat fast drying 923-610, Glasurit® Flardener 923-61 and Glasurit® thinner 352-30 in a ratio of 3:1:1, all compounds available from BASF Coatings GmbFI) was used as third coating composition (C-3).

3. Preparation of multilayer coating systems

3.1 Preparation of a comparative multilayer coating system (MC-C)

A steel panel is coated with a standard black electrocoat (CathoGuard® 580 Schwarz from BASF Coatings), padded (manual ruffling of the substrate using a 3M™ Scotch- Brite™ abrasive cloth) and subsequently cleaned with a cleaning composition (Glasurit® 700-1 ). First of all, using a spray gun (SATAjet® FIVLP 4000, entry pressure: 2 bar, pressure at the nozzle: 0.7 bar) a commercially available primer-surfacer (Glasurit® 285- 270 GrundfOller Pro, volume ratio of 5:1 :1, BASF Coatings GmbFI) is applied in two spray passes such that the resulting dry film thickness is 60 pm and then dried at 60°C for 30 minutes. After initial sanding by means of an eccentric sander (adhesive sanding sheets 150 mm P 500) and subsequent cleaning with a cleaning composition (Glasurit® 700-1), the second coating composition (see point 2.2) is applied with a spray gun such that the resulting dry film thickness is 10 to 20 pm and then dried until the surface appears matt. Afterwards, the third coating composition (see point 2.3) is applied with a spray gun such that the resulting dry film thickness is 50 to 60 pm and dried at 21 °C for 10 minutes. Finally, the formed second and third coating films are cured at 60°C for 30 minutes.

3.1 Preparation of the inventive peelable coating system (MC-I)

A commercially available car (model: VW, color: black) was cleaned in a car wash and masked accordingly. Afterwards, the first coating composition (see point 2.1) was applied with a spray gun (SATA jet 100 BF RP with a nozzle size of 2.0, entry pressure: 1.25 bar) in 5 spraying passes such that the resulting dry film thickness was 100 to 120 pm. After each spraying pass, the applied coating composition was flashed at 21 °C for 10 to 15 minutes. Afterwards, the formed first coating layer was cured at 21 °C for 60 minutes. Then, the second coating composition (see point 2.2) is applied with a spray gun such that the resulting dry film thickness is 10 to 20 pm and then dried until the surface appears matt. Afterwards, the third coating composition (see point 2.3) is applied with a spray gun such that the resulting dry film thickness is 50 to 60 pm and dried at 21 °C for 10 minutes. Finally, the formed second and third coating films are cured at 60°C for 30 minutes.

4. Results

4.1. Peeling behavior

The peelable coating system could be completely removed from the automotive by pulling at the damaged areas by hand without visually damaging the original finish. Therefore, the peeling behavior was rated with “OK”.

4.2. Residues on surface after peeling

No visual residues were left on the original finish (i.e. the original coating) of the automobile after fully removing the peelable coating system. Therefore, the rating was “No”.

4.3 Mechanical stability No visible defects could be detected in the peelable coating system after using the automotive for x month in road traffic. Thus, the mechanical stability was rated with “YES”.

4.4 Optical properties

The appearance of the automotive comprising the inventive peelable coating system was not visually distinct to the appearance of the comparative multilayer coating (MC- C) prepared by using the same second and third coating compositions. Therefore, application of a colored coating material onto the first coating layer formed from the first coating composition does not negatively impair the optical properties of the second coating material. The optical properties were therefore rated with “OK”.

5. Discussion of the results

The inventive peelable coating system shows a good peeling behavior and can be fully removed from the underlying original finish without damaging the finish by pulling on the intentionally damaged peelable coating system with the hand(s). The residue-free removal of the inventive peelable coating system renders subsequent cleaning of the original finish superfluous, thus reducing the costs associated with peelable coating system. Moreover, the mechanical stability of the peelable coating system is sufficiently high such that negative influences commonly encountered in road traffic, such as stone chipping, car washing, and different weather conditions, such as high humidity and irradiation by sunshine, does not result in visible defects in the peelable coating layer. Thus, the renewal intervals of the peelable coating layer and therefore also the maintenance costs are reduced. The first coating layer which is responsible for the peeling behavior of the peelable coating system is compatible with commercially available aqueous and solvent-based pigmented coating compositions, thus allowing to customize or personalize the automotive with a huge variety of colors, including effect colors.

In conclusion, the inventive peelable coating system allows to temporarily customize or personalize a substrate, such as an automotive, using commercially available refinish coating products without damaging the original finish. The sufficient mechanical stability as well as the high optical quality of the peelable coating system allow to customize or personalize a substrate at lower costs compared to the use of colored foils currently used to customize or personalize substrates.