Silane-based coating compositions comprising a metal alkoxide catalyst and an acid-functional polymer

Abstract

The present invention relates to a silane-based coating composition, in particular a clear coating composition, comprising a metal alkoxide catalyst and an acid-functional polymer. Furthermore, the present invention relates to a method for coating a substrate with the coating composition and to a coated substrate obtained by said method. Finally, the present invention relates to a multilayer coating and to a substrate coated with said multilayer coating.

Description

[0001] This invention relates to silane-based coating compositions, particularly varnish compositions, comprising metal alkoxide catalysts and acid-functionalized polymers. Furthermore, this invention relates to methods for coating substrates with these coating compositions and the coated substrates obtained by said methods. Finally, this invention relates to multilayer coatings and substrates coated with said multilayer coatings. Existing technology

[0002] In today's varnish industry, the use of isocyanates and tin catalysts as crosslinking agents is becoming increasingly undesirable due to increasingly stringent legal classifications and maximum permissible values.

[0003] However, polyisocyanates are commonly used crosslinking agents in many coating systems, especially varnishes. There are currently no suitable alternatives that meet future environmental, health, and safety requirements, as well as minimum technical requirements. To improve the economic efficiency of coating processes, rapid, low-temperature curing coating systems are needed.

[0004] However, coatings based solely on the condensation of alkoxysilanes often exhibit undesirable properties, such as severe post-curing and brittle films, making them unsuitable as clear coats in automotive applications. Customized clear coats are particularly necessary for automotive refinish applications due to the application of a non-crosslinked undercoat.

[0005] There is no alkoxysilane crosslinked clear coat that performs well in general automotive applications, especially for refinish paint applications, because the clear coat currently available cannot fully achieve important parameters such as rapid curing, rapid sandability and polishability, scratch resistance, good appearance, interlayer adhesion, moisture resistance and UV resistance, and high flexibility.

[0006] EP 2 641 925 A1 discloses coating compositions containing adducts of isocyanate-based alkyltrialkoxysilanes and diols. However, in the examples of EP 2 641 925 A1, these adducts are used with a large amount of polyacrylate polyol. When used as the sole resin with a suitable crosslinking catalyst, such as potassium neodecanoate and DBU, these adducts exhibit relatively long surface drying times and poor cross-cut adhesion even before constant climate testing.

[0007] WO 03 / 054049 discloses isocyanate-functionalized silanes as adhesion promoters in polyurethane-based adhesives or coatings. However, these silanes contain isocyanates, which are to be avoided in this invention.

[0008] JP-A-2005 015644 describes adducts of polyisocyanates and aminosilanes in an NCO:OH ratio of 1:0.05 to 1:0.9, i.e., with an excess of isocyanate groups. These adducts are used in combination with other resins in curable resin compositions.

[0009] Therefore, it is advantageous to use isocyanate-free coating compositions, preferably varnish compositions, which can be produced at low cost and can be cured at low temperatures. The resulting coating should exhibit good mechanical and optical properties, especially low short-wavelength values ​​and high flexibility. Furthermore, the use of tin-containing catalysts should be avoided.

[0010] Purpose

[0011] Therefore, the object of the present invention is to provide a fast-curing coating composition, preferably a varnish composition, that can be cured at low temperatures without the use of isocyanate or amino plastic crosslinking agents and tin-containing catalysts. This coating composition should be particularly suitable for automotive coatings, such as automotive OEM and automotive refinish coatings. The coating composition should have a long pot life and should be able to be produced at a low total material cost. The coating obtained from said coating composition should be solvent-resistant to exhibit good adhesion, scratch resistance, UV and weather resistance, high gloss, good appearance, and improved flexibility.

[0012] Technical solutions

[0013] The above objectives are achieved through the subject matter claimed in the claims and through preferred embodiments of the subject matter described in the following specification.

[0014] The first subject of this invention is therefore a coating composition comprising:

[0015] a) at least one silane compound R1 having an isocyanate content of less than 1% and comprising at least one silane group of general formula (I).

[0016] *-NR 1 X-SiR 2 a (OR 3 ) 3-a (I)

[0017] and optionally at least one silyl group of general formula (II)

[0018] *-N[X-SiR 2 a (OR 3 ) 3-a ] n [X'-SiR 2 b (OR 3 ) 3-b ]m (II)

[0019] in

[0020] X and X' are independently straight-chain and / or branched alkylene or cycloalkylene groups having 1-20 carbon atoms;

[0021] R 1 It is an alkyl group containing 1-10 carbon atoms.

[0022] R 2 R 3 Each of the alkyl, cycloalkyl, aryl, or aralkyl groups is independently an alkyl, cycloalkyl, aryl, or aralkyl group, and the carbon chain of the alkyl, cycloalkyl, aryl, or aralkyl group may be connected by non-adjacent oxygen, sulfur, or NR. a Group spacers, where R a It is alkyl, cycloalkyl, aryl, or aralkyl.

[0023] n and m are independent values ​​of 0-2, provided that m+n=2.

[0024] a and b are independently 0-2;

[0025] b) At least one catalyst of general formula (III) C1

[0026] z[C(R 4 (R) 5 (R) 6 )-(CH2) n -C(=O)-O - M z+ (III)

[0027] in

[0028] R 4 -R 6 Each of the residues is independently hydrogen or an alkyl group containing 1-6 carbon atoms, provided that residue R is present. 4 -R 6 The total number of carbon atoms in it is 3-8;

[0029] z is 1-4; and

[0030] n is 0 or 1-8

[0031] The condition is that,

[0032] If z = 1, then M is selected from Li, K, and Na;

[0033] If z = 2, then M is selected from Zn and Zr;

[0034] If z = 3, then M is selected from Bi and Al;

[0035] If z = 4, then M is selected from Zr and Ti;

[0036] c) At least one metal alkoxide C2;

[0037] d) At least one polymer P1 with an acid value greater than 10 mg KOH / g solid, determined according to DIN EN ISO 2114:2002-06 (Procedure A); and

[0038] e) One or more aprotic organic solvents.

[0039] The above-described coating composition is also referred to hereinafter as the coating composition of the present invention, and is therefore a subject of the present invention. Preferred embodiments of the coating compositions of the present invention will be apparent from the following description and from the dependent claims.

[0040] According to existing technology, it is surprising and unexpected for those skilled in the art that the objectives of this invention can be achieved by using a special silane compound R1 and an acid-functionalized polymer P1 in combination with a special catalyst mixture C1 and C2. The combination of the silane compound R1 and the acid-functionalized polymer P1 with the special catalysts C1 and C2 produces a low-curing coating composition that provides a coating with excellent mechanical and optical properties without the use of isocyanate or amino plastic crosslinking agents and tin-containing catalysts. Therefore, the coating compositions of this invention are particularly suitable for OEM repair and touch-up paint applications using low curing temperatures. Compared to varnishes prepared by using a combination of silane compound R1 and catalysts C1 and C2, the appearance, especially the short-wavelength value and flexibility, of the resulting varnish layer can be improved by using a metal alkoxide C2 in combination with catalyst C1 of general formula (III), silane compound R1, and acid-functionalized polymer P1. Furthermore, the addition of acid-functionalized polymer P1 allows for a significant reduction in the amount of expensive silane compound R1, thereby reducing the overall material cost of the coating compositions of this invention.

[0041] Another subject of the present invention is a method for forming a coating on a substrate (S), comprising the following steps:

[0042] (1) Apply the coating composition of the present invention to a substrate (S);

[0043] (2) A coating film is formed from the coating composition applied in step (1); and

[0044] (3) Curing the coating film formed in step (2).

[0045] Another subject of the present invention is a coated substrate obtained according to the method of the present invention.

[0046] Another subject of the invention is a multilayer coating comprising at least two coatings, preferably at least one primer layer and at least one varnish layer, wherein at least one coating, preferably the varnish layer, is formed from the coating composition of the invention.

[0047] The final subject of this invention is a substrate coated with the multilayer coating of this invention.

[0048] Detailed Explanation

[0049] Measurement methods for determining certain characteristic variables in the context of this invention are described in the Embodiments section. Unless otherwise expressly stated, these measurement methods are applied to the determination of the respective characteristic variables. When an official standard is mentioned in the context of this invention without any indication of an official validity period, it implicitly refers to the version of the standard valid on the date of submission, or, if no valid version exists at that time, the most recent valid version.

[0050] The term "silyl compound" refers to a compound comprising at least one silyl group of formula (I) or (II) above. The silyl group is attached to the backbone of the compound via an asterisk (*), preferably via a urea bond. As used herein, the "backbone" of a compound is the portion of the compound other than structure (I) and optionally (II). When a suitable backbone of the compound is a polymer, the silyl groups (I) and optionally (II) may be side-attached to the polymer chain, or they may be incorporated into the polymer chain, or a combination thereof.

[0051] The term "poly(meth)acrylate" refers to both polyacrylate and polymethacrylate. Poly(meth)acrylate may therefore contain acrylates and / or methacrylates and may contain other olefinically unsaturated monomers, such as styrene or acrylic acid.

[0052] The term "aliphatic" as used in this article includes the term "alicyclic" and refers to non-aromatic groups, structural moieties, and compounds, respectively.

[0053] All film thicknesses reported in the context of this invention should be understood as dry film thicknesses. This, therefore, in each case, refers to the thickness of the cured film. Thus, if a coating is reported to be applied at a specific film thickness, this means that the coating is applied to obtain the specified film thickness after curing.

[0054] All temperatures described in the context of this invention should be understood as the indoor temperature of the substrate or coated substrate. This does not therefore imply that the substrate itself needs to have the stated temperature.

[0055] The coating composition of the present invention:

[0056] The coating compositions of the present invention each contain at least one aprotic solvent, and are therefore preferably solvent-based coating compositions. In the context of the present invention, solvent-based coating compositions preferably contain less than 10% by weight, more preferably less than 5% by weight, more preferably less than 1% by weight, and very preferably 0% by weight of water and / or protic solvent, based on the total weight of the coating composition in each case.

[0057] Silyl compound R1(a):

[0058] The coating composition of the present invention comprises at least one silane compound R1 as a first essential component (a), having an isocyanate content of less than 1% (hereinafter also referred to as NCO content) and containing at least one silane group of general formula (I).

[0059] *-NR 1 X-SiR 2 a (OR 3 ) 3-a (I)

[0060] and optionally at least one silyl group of general formula (II)

[0061] *-N[X-SiR 2 a (OR 3 ) 3-a ] n [X'-SiR 2 b (OR 3 ) 3-b ] m (II)

[0062] in

[0063] R 1 -R 3 X, X', a, b, m, and n are as defined above. The silane groups of formulas (I) and (II) are bonded to the backbone of the silane compound R1 as described above via the *- symbol.

[0064] The silane compound R1 preferably contains less than 0.5%, more preferably 0.05-0%, of isocyanate content. This ensures that the silane compound R1 contains only a very low amount of free NCO groups or is substantially free of NCO groups, thus allowing its use in isocyanate-free coating compositions.

[0065] The lengths of the spacer groups X and X′ between the silane functional group and the organofunctional group used for the skeleton reaction with silane compound R1 can significantly affect the reactivity of organofunctional silanes. X and X′ in general formulas (I) and (II) preferably represent straight-chain alkylene groups having 1-10, more preferably 1-6, even more preferably 2-5, and very preferably 3 carbon atoms.

[0066] R in general formula (I) 1 Preferably, it contains 2-8 carbon atoms, more preferably 4-6 carbon atoms, and most preferably alkyl groups with 4 carbon atoms.

[0067] The preferred option is alkoxy (OR) 3 This affects the reactivity of the hydrolyzable silane group. Particularly preferred are groups that enhance the reactivity of the silane group, i.e., groups R that form good leaving groups. 3 Therefore, methoxy is preferred over ethoxy, and ethoxy is preferred over propoxy. Therefore, particularly preferably, R in formulas (I) and (II) 3 Each represents C1-C independently. 10 Alkyl, more preferably C1-C6 alkyl, very preferably C1 alkyl.

[0068] The silyl group of general formula (II) contains two alkoxysilane moieties, so the sum of n and m is 2. The corresponding alkoxysilane moieties can be the same or different from each other. In the case of different alkoxysilane moieties, if m = n = 1, then R 3 and R 4 Different. In the case of the same alkoxysilane structural moiety, R 3 and R 4 The same and m = n = 1, or m = 0 and n = 2, or vice versa.

[0069] The preferred silane group of formula (I) and, if present, the silane group of formula (II) each contain three alkoxy structural moieties. Therefore, a in formulas (I) and (II) and b in formula (II) are advantageously independent of each other and are 0.

[0070] Silyl compound R1(a) can be produced by reacting at least one polyisocyanate with at least one compound of general formula (Ia).

[0071] HNR 1 -X-SiR 2 a (OR 3 ) 3-a (Ia)

[0072] and optionally react with at least one compound of general formula (IIa) to prepare

[0073] HN[X-SiR 2a (OR 3 ) 3-a ] n [X'-SiR 2 b (OR 3 ) 3-b ] m (IIa).

[0074] R in general formulas (Ia) and (IIa) 1 -R 3 X, X', a, b, m, and n are defined as above.

[0075] In principle, all aliphatic, alicyclic, aryliphatic, and aromatic polyisocyanates can be used as polyisocyanates. Examples of preferred polyisocyanates include: 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane 4,4′-diisocyanate, diphenylmethane 2,4′-diisocyanate, terephthalic diisocyanate, biphenyl diisocyanate, 3,3′-dimethyl-4,4′-diphenyl diisocyanate, tetramethylene 1,4-diisocyanate, hexamethylene 1,6-diisocyanate, 2,2,4-trimethylhexane 1,6-diisocyanate, isophorone diisocyanate, and ethylene... 1,12-dodecane diisocyanate, cyclobutane 1,3-diisocyanate, cyclohexane 1,3-diisocyanate, cyclohexane 1,4-diisocyanate, methylcyclohexyl diisocyanate, hexahydrotoluene 2,4-diisocyanate, hexahydrotoluene 2,6-diisocyanate, hexahydrobenzene 1,3-diisocyanate, hexahydrobenzene 1,4-diisocyanate, perhydrodiphenylmethane 2,4′-diisocyanate, 4,4′-methylene dicyclohexyl diisocyanate (e.g., from Covestro AG) W), tetramethylxylyl diisocyanate (e.g., from American Cyanamid) The mixture of polyisocyanates mentioned above. Further preferred polyisocyanates are those derived from polyisocyanates through trimerization, dimerization, urethane formation, biuretization, or allophanatization. Particularly preferred polyisocyanates are hexamethylene diisocyanate diketone, hexamethylene diisocyanate, 1-isocyanate-4-[(4-isocyanate-cyclohexyl)-methyl]cyclohexane, and hexamethylene diisocyanate trimers.

[0076] The preferred compound (Ia) of the present invention is an aminoalkyltrialkoxysilane, such as preferably 2-aminoethyltrimethoxysilane, 2-aminoethyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 4-aminobutyltrimethoxysilane, and 4-aminobutyltriethoxysilane. Particularly preferred compounds (Ia) are N-(2-(trimethoxysilyl)ethyl)alkylamine, N-(3-(trimethoxysilyl)propyl)alkylamine, N-(4-(trimethoxysilyl)butyl)alkylamine, N-(2-(triethoxysilyl)ethyl)alkylamine, N-(3-(triethoxysilyl)propyl)alkylamine, and / or N-(4-(triethoxysilyl)butyl)alkylamine. Particularly preferred aminosilanes of formula (Ia) are α-aminosilanes (X = CH2) and γ-aminosilanes (X = n-propyl), with γ-aminosilanes being the most preferred in this invention. Particularly preferred are N-alkylamino-alkyl-trialkoxysilanes, with n-alkylamino-propyltrimethoxysilanes being the most preferred, such as n-butylamino-propyl-trimethoxysilane. This type of aminosilane may be marketed, for example, under trade names. Obtained from DEGUSSA or Sourced from Momentive.

[0077] Preferred compounds (IIa) are bis(2-ethyltrimethoxysilyl)amine, bis(3-propyltrimethoxysilyl)amine, bis(4-butyltrimethoxysilyl)amine, bis(2-ethyltriethoxysilyl)amine, bis(3-propyltriethoxysilyl)amine, and / or bis(4-butyltriethoxysilyl)amine. Bis(3-propyltrimethoxysilyl)amine is particularly preferred.

[0078] Preferred compounds of this type (IIa) may be marketed, for example, under a trademark. Obtained from DEGUSSA or Sourced from Momentive.

[0079] The reaction of at least one polyisocyanate with a compound of general formula (Ia) and optionally a compound of general formula (IIa) can be carried out without solvent or in the presence of an aprotic solvent until substantially all, preferably all, of the free isocyanate groups of the at least one polyisocyanate are consumed. The reaction is preferably carried out in an inert gas at a temperature not exceeding 100°C, preferably not exceeding 60°C.

[0080] According to the present invention, preferably, the silane compound R1 contains 50-100 mol%, preferably 80-100 mol%, more preferably 95-100 mol% of at least one silane group of general formula (I) and 0-50 mol%, preferably 0-20 mol%, more preferably 0-5 mol% of at least one silane group of general formula (II), in each case based on the total amount of silane groups of general formula (I) and (II). It has been found that the ratio of silane groups of general formula (I) to silane groups of general formula (II) has a particularly critical effect on the occurrence of cracks in the resulting coating. In this relationship, generally speaking, as the proportion of monosilane groups of general formula (I) decreases and as the proportion of disilane groups of general formula (II) increases, the occurrence of cracks in the resulting coating increases. Therefore, a particularly preferred silane compound R1 contains 100 mol% of silane groups of general formula (I) and 0 mol% of silane groups of general formula (II).

[0081] A very surprising and also very advantageous fact is that, while reducing cracking by increasing the proportion of monosilyl groups of general formula (I) and decreasing the proportion of disilyl groups of general formula (II), the scratch resistance of the resulting coating is reduced by only a very slight decrease.

[0082] The silane compound R1 is preferably present in a total amount of 5-45% by weight, more preferably 10-40% by weight, and most preferably 12-35% by weight, in each case based on the total weight of the coating composition. This amount of silane compound R1 used in the coating composition is a calculated theoretical amount, based on the premise that the sum of the weights of the reactants used to produce the silane compound R1 equals the final weight of the silane compound R1.

[0083] Catalyst C1(b) of general formula (III):

[0084] The coating composition of the present invention comprises at least one catalyst C1 of general formula (III) as a second essential component (b).

[0085] z[C(R 4 (R) 5 (R) 6 )-(CH2) n -C(=O)-O - M z+ (III)

[0086] in

[0087] R 4 -R 6 Each of the residues is independently hydrogen or an alkyl group containing 1-6 carbon atoms, provided that residue R is present. 4 -R 6 The total number of carbon atoms in it is 3-8;

[0088] z is 1-4; and

[0089] n is 0 or 1-8

[0090] The condition is that,

[0091] If z = 1, then M is selected from Li, K, and Na;

[0092] If z = 2, then M is selected from Zn and Zr;

[0093] If z = 3, then M is selected from Bi and Al;

[0094] If z = 4, then M is selected from Zr and Ti.

[0095] Residue R in general formula (III) 4 -R 6 The total number of carbon atoms in the sample is preferably 3-5 or 5-8.

[0096] In general formula (III), z is preferably 1, 3 or 4, more preferably 1 or 4.

[0097] In general formula (III), n is preferably 0 or 2-6, more preferably 0 or 4. If n is 0, then the residue R in general formula (III) 4 and R 5 Each is independently a straight-chain or branched C3-C5 alkyl group, and residue R 6 It is a methyl group, provided that the residue R is present. 4 -R 6 The sum of all carbon atoms is 8. If n in general formula (III) is 1-8, preferably 4, then residue R 4 -R 6 Each is a methyl group, independent of the others.

[0098] In general formula (III), M is preferably potassium, lithium or titanium, with potassium or titanium being more preferred.

[0099] Particularly preferred catalyst C1 of general formula (III) is a potassium, lithium, or titanium neodecanoate and / or ethylhexanoate, preferably potassium neodecanoate (I), potassium 2-ethylhexanoate (I), titanium neodecanoate (IV), or titanium 2-ethylhexanoate (IV). Very preferably, the coating composition of the present invention contains exactly one catalyst C1, particularly preferably potassium neodecanoate (I), titanium neodecanoate (IV), or titanium 2-ethylhexanoate (IV). Potassium neodecanoate (I) is particularly preferred because the resulting coating exhibits a significantly improved appearance.

[0100] Typically, catalyst C1 of formula (III) is supplied by the manufacturer in an acid-stabilized form. This type of acid-stabilized catalyst C1 of formula (III) is preferred not only because of its higher storage stability but also because it introduces free acid into the coating composition according to the invention. This type of free acid is known to be beneficial when combined with catalyst C2, and furthermore, it improves silane hydrolysis and thus network formation. The stabilizing acid is typically the protonated residue C(R) contained in general formula (III). 4 (R) 5 (R) 6 )-(CH2) n -C(=O)-OH. If the catalyst C1 is supplied in the form of a stabilizing acid C(R) 4 (R) 5 (R) 6 )-(CH2) n If -C(=O)-OH, then the content of this acid is classified into the carboxylic acid of formula (VI) as described below.

[0101] The amount of at least one catalyst C1, particularly potassium neodecanoate (I) or titanium neodecanoate (IV), is preferably 1-50 mmol, more preferably 5-40 mmol, and most preferably 15-35 mmol of metal, in each case based on 100 g of silane compound R1 solid.

[0102] Metal alkoxide C2(c):

[0103] The coating composition of the present invention comprises at least one metal alkoxide as a third essential component (c). The metal alkoxide acts as a co-catalyst and, in combination with catalyst C1, preferably potassium neodecanoate (I) or titanium neodecanoate (IV), results in improved resistance to humid conditions compared to compositions containing nitrogen compounds such as DBU as co-catalysts. While not wishing to be bound by any particular theory, it is speculated that the metal alkoxide may participate in the condensation reaction of the silane compound R1 during the curing process.

[0104] At least one metal alkoxide C2 is preferably selected from metal alkoxides of general formula (IV).

[0105] M 1 [(OR 7 ) m (R 8 ) n-m ] n (IV)

[0106] in

[0107] R 7 Is it a straight-chain or branched C1-C? 10 alkyl,

[0108] R 8It is a halogen group, an acetylacetone group, an alkyl acetoacetate group, or an ethanolamine group.

[0109] M 1 It represents at least one metal selected from silicon, titanium, tantalum, zirconium, boron, aluminum, magnesium, or zinc.

[0110] m is an integer between 0 and 4, and

[0111] n represents M 1 Its valence is 2-5.

[0112] R in general formula (IV) 7 Preferably selected from C3-C5 alkyl groups, more preferably selected from C3 or C4 alkyl groups.

[0113] R in general formula (IV) 8 Preferably, it is an alkyl acetoacetate group, more preferably an ethyl acetoacetate group.

[0114] In general formula (IV), m is preferably 0 or 1-4, more preferably 0 or 2-4, and very preferably 0, 2 or 4.

[0115] M in general formula (IV) 1 The preferred metal is selected from titanium, and n represents the valence of 4.

[0116] The catalyst C2 is particularly preferred and selected from titanium isopropoxide (IV) and / or titanium n-butoxide (IV) and / or bis(ethyl acetoacetate) diisopropoxide (IV), with titanium isopropoxide (IV) being the most preferred.

[0117] At least one metal alkoxide C2, preferably a metal alkoxide of general formula (III), preferably present in a total amount of 2.5-40 millimoles of metal, in each case based on 100 grams of silane compound R1 solid.

[0118] The metal / metal ratio of the catalyst C1 of general formula (II) to at least one metal alkoxide C2, preferably a metal alkoxide of general formula (III), is preferably 1:2 to 2:1. The use of the catalyst mixture at the above ratio results in improved tolerance to humid conditions, thus significantly reducing blistering and whitening of the cured coating obtained from the coating compositions of the present invention upon exposure to humid conditions compared to cured coatings made using a nitrogen-containing co-catalyst, such as DBU, instead of the metal alkoxide C2.

[0119] Acid-functionalized polymer P1(d):

[0120] As a fourth essential component, the coating composition of the present invention comprises at least one polymer P1 (hereinafter referred to as acid-functional polymer P1) with an acid value greater than 10 mg KOH / g solids.

[0121] Suitable polymer P1 is selected from homopolymers or copolymers of unsaturated acids, polyurethanes having at least one anionic group, polyurethane (meth)acrylates having at least one anionic group, and mixtures thereof, preferably homopolymers or copolymers of unsaturated acids, and very preferably homopolymers or copolymers of unsaturated carboxylic acids. The term "polymer having at least one anionic group" refers to a polymer having at least one group that can form an anionic group under specific conditions (e.g., by reacting with a suitable neutralizing agent). The term "polymer" is well known to those skilled in the art and refers to compounds produced by polymerizing the same or different types of monomers, including homopolymers, copolymers, and trimers. The term "homogeneous polymer" refers to a polymer prepared by polymerizing only one type of monomer, while the term "copolymer" refers to a polymer prepared by polymerizing at least two different monomers.

[0122] Homopolymers or copolymers of unsaturated acids, preferably unsaturated carboxylic acids, can be prepared by known methods such as bulk polymerization or solution polymerization. Polymerization can be carried out as volatile free radical polymerization. The free radicals are typically provided by redox initiators or organic peroxides or azo compounds. Suitable initiators are selected from ammonium persulfate, potassium persulfate, sodium metabisulfite, hydrogen peroxide, tert-butyl hydroperoxide, dilauryl peroxide, tert-butyl peroxybenzoate, tert-butyl per-2-ethylhexanoate, di-tert-butyl peroxide, 2,2'-azobutyronitrile (isobutyronitrile), 2,2'-azobis(isovalerate), and redox initiators such as ammonium persulfate and sodium metabisulfite with ferric(II) ammonium sulfate. Furthermore, polymerization can be carried out as anionic, cationic, or controlled radical polymerization.

[0123] In this regard, suitable groups capable of forming anions are selected from carboxylic acid groups, sulfonic acid groups, phosphonic acid groups and mixtures thereof, with carboxylic acid groups being preferred.

[0124] Polymer P1, preferably capable of forming anions, has groups that are only partially neutralized or not neutralized at all. Therefore, the degree of neutralization of polymer P1 is preferably 0-20%, more preferably 0-10%, and very preferably 0%. A degree of neutralization of 0% means that all acid functional groups of polymer P1 exist in the coating composition in a non-neutralized form, i.e., none of the acid functional groups of polymer P1 react with a neutralizing agent such as a alkali. Undesirably, the presence of a sufficiently large amount of acid functional groups in polymer P1 leads to the formation of a multifunctional mixed matrix during the curing process of the coating composition through silane-silane condensation, silane-titanium condensation, and titanium-carboxylic acid complexation. This results in an improvement in the appearance, particularly the short-wavelength value and flexibility, of the cured coating obtained from the coating composition.

[0125] Preferred polymer P1 contains in polymeric form

[0126] (i) at least one unsaturated monomer M1 having at least one group capable of forming an anion;

[0127] (ii) Optionally, at least one unsaturated monomer M2 selected from esters of (meth)acrylic acid having at least one alkyl group substituted with a hydroxyl group;

[0128] (iii) Optionally at least one lactone;

[0129] (iv) Optionally, at least one other unsaturated monomer M3 different from monomers M1 and M2; and

[0130] (v) Optionally at least one cyclic carboxylic anhydride.

[0131] The term "in polymeric form" in the context of this invention should be understood to mean that compounds (i) and optionally compounds (ii)-(v) are used as starting materials for the preparation of polymer P1, i.e., polymer P1 comprises the reaction products of compounds (i) and optionally compounds (ii)-(iv), preferably consisting of the reaction products of compounds (i) and optionally compounds (ii)-(iv).

[0132] Suitable monomer M1 is selected from (meth)acrylic acid, ethylacrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid; olefinic unsaturated sulfonic acids and phosphonic acids and their esters; and mono(meth)acryloyloxyethyl maleate, mono(meth)acryloyloxyethyl succinate and mono(meth)acryloyloxyethyl phthalate, preferably (meth)acrylic acid, very preferably acrylic acid.

[0133] At least one monomer M1, particularly acrylic acid, is preferably present in a total amount of 1-100% by weight, more preferably 5-50% by weight, more preferably 10-20% by weight, and very preferably 12-17% by weight, based on the total amount of compounds (i) to (v). Thus, the total weight of monomer M1 is based on the total amount of all monomers M1-M3, lactones, and cyclic carboxylic anhydrides present in polymer P1.

[0134] In addition to at least one monomer M1, the preferred polymer P1 comprises at least one unsaturated monomer M2 selected from esters of (meth)acrylic acid having at least one alkyl group substituted with a hydroxyl group. Suitable monomer M2 is selected from 2-hydroxyethyl (meth)acrylic acid, 2-hydroxypropyl (meth)acrylic acid, 3-hydroxypropyl (meth)acrylic acid, 3-hydroxybutyl (meth)acrylic acid, 4-hydroxybutyl (meth)acrylic acid, and mixtures thereof, with 2-hydroxyethyl (meth)acrylic acid being particularly preferred.

[0135] At least one monomer M2, particularly 2-hydroxyethyl methacrylate, is present in a total amount of compounds (i) to (v) preferably 1-30% by weight, more preferably 5-25% by weight, more preferably 10-20% by weight, and very preferably 12-15% by weight.

[0136] Particularly preferred is that at least one polymer P1 contains at least one monomer M2 and at least one lactone in addition to monomer M1. Using said at least one lactone produces a brush-like polymer with polylactone side chains and results in improved polymer flexibility.

[0137] Suitable lactones are compounds of the general formula (V):

[0138]

[0139] in

[0140] p is 1-10, preferably 1-8, more preferably 3-6, and very preferably an integer of 5. Therefore, the lactone of the particularly preferred general formula (V) is ε-caprolactone.

[0141] At least one lactone, particularly ε-caprolactone, is preferably present in a total amount of 0.5-25% by weight, more preferably 1-20% by weight, more preferably 5-15% by weight, and very preferably 5-11% by weight, based on the total amount of compounds (i) to (v).

[0142] Preferably, polymer P1 further comprises, in addition to the monomers M1, M2 and lactone described above, at least one unsaturated monomer M3 that is different from monomers M1 and M2. Suitable monomer M3 is selected from alkyl (meth)acrylates (M3-1) and / or unsaturated monomers (M3-2) containing at least one aromatic moiety.

[0143] In this regard, the preferred alkyl methacrylate (M3-1) is selected from methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, n-butyl methacrylate, ethylhexyl methacrylate, 3,3,5-trimethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, cycloalkyl methacrylate such as cyclopentyl methacrylate, isobornyl methacrylate, cyclohexyl methacrylate and mixtures thereof, preferably n-butyl methacrylate and / or ethylhexyl methacrylate.

[0144] The preferred unsaturated monomer (M3-2) containing at least one aromatic group is selected from vinyl aromatic compounds, such as styrene, α-methylstyrene, vinyltoluene, tert-butylstyrene and mixtures thereof, with styrene being preferred.

[0145] If present, polymer P1 may contain at least one other monomer M3, the total amount of which in each case is 1-75% by weight, preferably 5-70% by weight, more preferably 10-65% by weight, and very preferably 50-60% by weight, based on the total amount of compounds (i) to (v). If polymer P1 is prepared using more than one monomer M3, the above amounts refer to the total amount of all monomers M3 present in polymer P1.

[0146] The suitable amount of (meth)acrylate alkyl ester (M3-1), particularly n-butyl methyl acrylate and / or ethylhexyl acrylate, is 10-60 wt%, preferably 30-55 wt%, more preferably 35-50 wt%, and very preferably 37-46 wt%, based on the total amount of compounds (i) to (v). The suitable amount of the unsaturated monomer (M3-2) containing at least one aromatic group, preferably styrene, is 1-30 wt%, preferably 5-25 wt%, more preferably 10-20 wt%, and very preferably 14-17 wt%, based on the total amount of compounds (i) to (v) in each case.

[0147] Polymer P1 preferably contains alkyl methacrylate (M3-1) and an unsaturated monomer (M3-2) comprising at least one aromatic moiety in a weight ratio of 5:1 to 1:1, more preferably 4:1 to 1:1, and very preferably 3:1 to 2:1.

[0148] Particularly preferably, polymer P1—in polymeric form—contains at least one cyclic carboxylic anhydride. Using said anhydride increases the acid value of polymer P1. A higher acid value for polymer P1 is advantageous because improved adhesion is obtained when using polymer P1 with a higher acid value. Suitable cyclic carboxylic anhydrides are selected from aromatic and aliphatic carboxylic anhydrides, with aliphatic carboxylic anhydrides being preferred. Particularly preferably, hexahydrophthalic anhydride is used as the cyclic carboxylic anhydride.

[0149] Preferably, polymer P1 contains at least one cyclic carboxylic anhydride, preferably hexahydrophthalic anhydride, the total amount of which in each case is 1-30% by weight, more preferably 5-25% by weight, even more preferably 8-15% by weight, and very preferably 5-11% by weight, based on the total amount of compounds (i) to (v).

[0150] Therefore, the particularly preferred polymer P1 comprises, in polymeric form, and is based on the total amount of compounds (i) to (vi):

[0151] (i) 5-50% by weight, preferably 12-15% by weight, at least one unsaturated monomer M1 having at least one group capable of forming an anion, preferably acrylic acid;

[0152] (ii) 1-30% by weight, 12-14% by weight of at least one monomer M2, wherein the monomer M2 is selected from esters of (meth)acrylic acid having an alkyl group substituted with at least one hydroxyl group, preferably 2-hydroxyethyl methacrylate.

[0153] (iii) 0.5-25% by weight, preferably 5-11% by weight of at least one lactone, preferably at least one lactone of general formula (V), very preferably ε-caprolactone;

[0154] (iv) 10-60% by weight, preferably 37-41% by weight, at least one (meth)acrylate alkyl ester (M3-1), preferably n-butyl methyl acrylate and / or ethylhexyl acrylate;

[0155] (v) 1-30% by weight, preferably 14-16% by weight, of at least one unsaturated monomer (M3-2) containing at least one aromatic group, preferably styrene; and

[0156] (vi) 1-30% by weight, preferably 9-11% by weight, of at least one cyclic carboxylic anhydride, preferably hexahydrophthalic anhydride.

[0157] Therefore, the further particularly preferred polymer P1 comprises, in polymeric form, and is based on the total amount of compounds (i) to (v):

[0158] (i) 5-50% by weight, preferably 14-16% by weight, at least one unsaturated monomer M1 having at least one group capable of forming an anion, preferably acrylic acid;

[0159] (ii) 1-30% by weight, 13-15% by weight, at least one monomer M2 selected from alkyl methacrylates having at least one hydroxyl group substituted, preferably 2-hydroxyethyl methacrylate;

[0160] (iii) 10-60% by weight, preferably 41-44% by weight, at least one (meth)acrylate alkyl ester (M3-1), preferably n-butyl methyl acrylate and / or ethylhexyl acrylate;

[0161] (iv) 1-30% by weight, preferably 15-17% by weight, of at least one unsaturated monomer (M3-2) containing at least one aromatic group, preferably styrene; and

[0162] (v) 1-30% by weight, preferably 10-12% by weight, of at least one cyclic carboxylic anhydride, preferably hexahydrophthalic anhydride.

[0163] According to DIN EN ISO 2114:2002-06 (Procedure A), the acid value of the polymer P1 is preferably 15-400 mg KOH / g solid, more preferably 30-300 mg KOH / g solid, even more preferably 60-200 mg KOH / g solid, and very preferably 90-130 mg KOH / g solid.

[0164] The weight-average molecular weight (Mw) of polymer P1 is preferably 1,000-10,000 g / mol, more preferably 3,000-8,000 g / mol, even more preferably 4,000-6,000 g / mol, and very preferably 4,800-5,400 g / mol. Furthermore, the number-average molecular weight (Mn) of polymer P1 is preferably 450-4,000 g / mol, more preferably 500-3,000 g / mol, even more preferably 800-2,000 g / mol, and very preferably 900-1,300 g / mol. According to DIN 55672-1:2016-03, both weight-average and number-average molecular weights can be determined by GPC using polystyrene as an internal standard.

[0165] The polydispersity D (Mw / Mn) of polymer P1 is preferably 2.0-6.5, more preferably 3.0-6.0, and very preferably 4.3-4.8.

[0166] The polymer P1 used according to the present invention can be prepared by polymerizing a mixture M comprising monomer M1 and optionally monomers M2, M3 and lactone. The polymer P1-1 can then be reacted with a cyclic carboxylic anhydride to increase the acid value of the obtained polymer P1.

[0167] Therefore, polymer P1 can be obtained through the following methods

[0168] (a) Polymerize a mixture M comprising the following components:

[0169] (i) at least one unsaturated monomer M1 having at least one group capable of forming an anion;

[0170] (ii) Optionally, at least one unsaturated monomer M2 selected from esters of (meth)acrylic acid having at least one alkyl group substituted with a hydroxyl group;

[0171] (iii) Optionally, at least one other monomer M3 different from monomers M1 and M2

[0172] (iv) optionally at least one lactone; and

[0173] (b) Optionally, the polymer obtained in step (a) is reacted with at least one cyclic carboxylic anhydride.

[0174] Suitable monomers M1 to M3, lactones, and cyclic carboxylic anhydrides are those disclosed above with respect to polymer P1.

[0175] At least one unsaturated monomer M1 having at least one group capable of forming an anion, particularly acrylic acid, is preferably present in the mixture M in a total amount of 5-35% by weight, more preferably 7-30% by weight, even more preferably 10-25% by weight, and very preferably 12-19% by weight.

[0176] At least one monomer M2, particularly 2-hydroxyethyl methacrylate, is preferably present in the mixture M in a total amount of 5-30% by weight, more preferably 7-25% by weight, even more preferably 10-20% by weight, and very preferably 12-18% by weight.

[0177] At least one other monomer M3, different from monomers M1 and M2, particularly n-butyl methyl acrylate and / or ethylhexyl acrylate and / or styrene, is present in the mixture M in a total amount of 40-80% by weight, more preferably 45-75% by weight, even more preferably 50-70% by weight, and very preferably 57-65% by weight.

[0178] In this regard, alkyl (meth)acrylate (M3-1) is preferred, n-butyl methyl acrylate and / or ethylhexyl acrylate are preferred, in each case present in the mixture M in a total amount of 25-65% by weight, more preferably 30-60% by weight, even more preferably 35-55% by weight, and very preferably 41-50% by weight.

[0179] In this regard, it is further preferred to contain an unsaturated monomer (M3-2) comprising at least one aromatic group, preferably styrene in each case in an amount of 1-40% by weight, more preferably 5-30% by weight, even more preferably 10-25% by weight, and very preferably 15-20% by weight in the total amount of mixture M.

[0180] At least one lactone, particularly ε-caprolactone, is preferably present in the mixture M in a total amount of 1-30% by weight, more preferably 3-25% by weight, even more preferably 4-20% by weight, and very preferably 5-13% by weight.

[0181] Preferably, the total amount of mixture M in each case is 1-30% by weight, more preferably 5-25% by weight, even more preferably 8-20% by weight, and very preferably 10-15% by weight of cyclic carboxylic anhydride, preferably hexahydrophthalic anhydride, reacting with the polymer obtained in step (a).

[0182] Therefore, a particularly preferred polymer P1 is obtained by the following:

[0183] (a) The polymerization is based on the total amount of mixture M containing the following components:

[0184] (i) 5-35% by weight, preferably 12-17% by weight of acrylic acid (monomer M1);

[0185] (ii) 5-30% by weight, preferably 12-17% by weight 2-hydroxyethyl methacrylate (monomer M2);

[0186] (iii) 25-65% by weight, preferably 41-47% by weight of n-butyl methyl acrylate and / or ethylhexyl acrylate (monomer M3-1);

[0187] (iv) 1-40% by weight, preferably 15-20% by weight styrene (monomer M3-2);

[0188] (v) 1-30 wt%, preferably 5-15 wt% ε-caprolactone; and

[0189] (b) React the polymer obtained in step (a) with hexahydrophthalic anhydride in each case in an amount of 1-30% by weight, preferably 10-15% by weight, based on the total amount of mixture M.

[0190] Therefore, the further particularly preferred polymer P1 is obtained by the following:

[0191] (a) The polymerization is based on the total amount of mixture M containing the following components:

[0192] (i) 5-35% by weight, preferably 16-19% by weight of acrylic acid (monomer M1);

[0193] (ii) 5-30% by weight, preferably 15-18% by weight, 2-hydroxyethyl methacrylate (monomer M2);

[0194] (iii) 25-65% by weight, preferably 45-50% by weight of n-butyl methyl acrylate and / or ethylhexyl acrylate (monomer M3-1);

[0195] (iv) 1-40% by weight, preferably 15-20% by weight styrene (monomer M3-2);

[0196] (b) React the polymer obtained in step (a) with hexahydrophthalic anhydride in each case in an amount of 1-30% by weight, preferably 10-15% by weight, based on the total amount of mixture M.

[0197] At least one polymer P1 having an acid value of at least 10 mg KOH / g solids is present in each case in a total amount of preferably 0.1-15% by weight, more preferably 0.5-10% by weight, and most preferably 1.5-8% by weight, based on the total weight of the coating composition.

[0198] Aprotic solvent (e):

[0199] The coating composition of the present invention is a solvent-based coating composition, and therefore contains at least one aprotic solvent as a fifth essential component (e). The aprotic solvent in the coating composition is chemically inert to the silane compound R1 and the acid-functionalized polymer P1, that is, they do not react with the silane compound R1 and the acid-functionalized polymer P1 during the storage and curing process of the coating composition of the present invention.

[0200] Suitable aprotic solvents are selected from aliphatic and / or aromatic hydrocarbons, such as toluene, xylene, solvent naphtha, Solvesso 100, or... (From APAL), ketones such as acetone, methyl ethyl ketone, or methyl amyl ketone, esters such as ethyl acetate, butyl acetate, amyl acetate, or ethyl ethoxypropionate, ethers, or mixtures of the above solvents. The non-protic solvent or solvent mixture preferably has a water content of no more than 1% by weight, more preferably no more than 0.5% by weight, based on the solvent. However, some additives or catalysts used herein are sold in protic organic solvents, and therefore in some cases, it is unavoidable to introduce some unwanted protic solvents unless solvent exchange is performed before their use. Such amounts are generally negligible if the amount of such protic solvents remains within the above limits. If unwanted premature crosslinking occurs due to the presence of protic solvents, for example, introduced by additives, it is preferable to introduce such additives into the coating composition just before application. Another possibility is to perform solvent exchange.

[0201] As mentioned above, the coating compositions of the present invention preferably contain less than 10% by weight, more preferably less than 5% by weight, more preferably less than 1% by weight, and very preferably 0% by weight of water and / or a proton solvent, based on the total weight of the coating composition in each case. Since the silyl compound R1 reacts with water and the proton solvent, the solvent is preferably absent to maximize the pot life and storage stability of the coating compositions of the present invention.

[0202] Aprotic solvents are typically introduced using a solution or dispersion of a silane compound R1 and an acid-functionalized polymer P1 in an aprotic solvent or a mixture of aprotic solvents. Additional amounts are introduced to adjust the viscosity of the coating composition to a suitable applied viscosity. At least one aprotic solvent is preferably present in a total amount of 1-70% by weight, more preferably 20-60% by weight, and most preferably 30-50% by weight, based on the total weight of the coating composition in each case.

[0203] Other optional components of the coating composition of the present invention:

[0204] Carboxylic acids of general formula (VI):

[0205] The coating composition of the present invention may further comprise at least one carboxylic acid of general formula (VI).

[0206] C(R 4 (R) 5 (R) 6 )-(CH2) n -C(=O)-OH (VI)

[0207] in

[0208] R 4 -R 6 Each of the residues is independently hydrogen or an alkyl group containing 1-6 carbon atoms, provided that residue R is present. 4 -R 6 The total number of carbon atoms in the sample is 3-8, preferably 5-8; and

[0209] n is 0 or 1-8, preferably 0 or 4.

[0210] The particularly preferred carboxylic acid of general formula (VI) is the free carboxylic acid corresponding to the carboxylate anion of the catalyst of general formula (III). The carboxylic acid of general formula (VI) is introduced into the coating composition of the present invention by using the catalyst C1 stabilized with the carboxylic acid described above.

[0211] The preferred carboxylic acid of general formula (VI) is neodecanoic acid.

[0212] At least one carboxylic acid of general formula (VI), preferably neodecanoic acid, is present in each case based on the total amount of catalyst C1 of general formula (III) in a total amount preferably 0-80% by weight, more preferably 30-70% by weight, and very preferably 50-60% by weight.

[0213] Epoxy functional compounds of general formula (VII):

[0214] The coating compositions of the present invention may further comprise at least one epoxy functional compound of general formula (VII).

[0215] (X) n -R 9 -Ox (VII)

[0216] in

[0217] Ox is an ethylene oxide group;

[0218] R 9 It is an aliphatic hydrocarbon group containing 2-15 carbon atoms and optionally including an ether group and / or an ester group;

[0219] n is 1-5; and

[0220] X is either Ox or *-Si(R) independently of each other. g ) 3-v (R h ) v Group, where v is 0 or 1, R g It is an alkoxy group containing 1-4 carbon atoms, and R h It is an alkyl group containing 1-4 carbon atoms or an alkoxy group containing 1-4 carbon atoms.

[0221] R in general formula (VII) 9 The preferred group is an aliphatic hydrocarbon group *-(CH2)3-O-CH2- # Or cyclohexylethyl. The symbol * indicates the aliphatic hydrocarbon group *-(CH2)3-O-CH2- # It is attached to the X residue, and the symbol # refers to the hydrocarbon group *-(CH2)3-O-CH2- # Linked to an ethylene oxide group. From R 9 It is an aliphatic hydrocarbon group *-(CH2)3-O-CH2- # The structure of the epoxy functional compound derived from general formula (VII) is therefore (X). n -(CH2)3-O-CH2-Ox.

[0222] In general formula (VII), n is preferably 1.

[0223] When the X group is an ethylene oxide group, the compound of general formula (VII) is an aliphatic diglycidyl ether, an aliphatic polyglycidyl ether, an aliphatic diglycidyl ester and / or an aliphatic polyglycidyl ester.

[0224] Examples of aliphatic di- or polyglycidyl ethers are 1,4-butanediol-diglycidyl ether (Heloxy67), 1,6-hexanediol-diglycidyl ether (Heloxy modifier HD), trimethylolpropane triglycidyl ether (Heloxy48) and neopentyl glycol diglycidyl ether (Heloxy68), hydrogenated bisphenol A diglycidyl ether (e.g., sold under the trade names Epaloy 5000 and Epaloy 5001 from CVC Specialty Chemicals; or under the trade name YX8000 from JapaneseEpoxy Resins Co., Ltd.), and cyclohexane dimethylol diglycidyl ether (e.g., sold under the trade name Heloxy). 107 sold from Hexion), tricyclodecanediethanol diglycidyl ether (e.g., sold from Adeka under the trade name EP4088S), compounds synthesized from 2,2-bis(hydroxymethyl)-1,3-propanediol and 2-(chloromethyl)ethylene oxide (Basocoll OV), or glycerol diglycidyl ether.

[0225] Examples of aliphatic di or polyglycidyl esters include glycidyl esters of linoleic acid dimer (e.g., sold under the trade name Erisys GS-120 from CVC Specialty Chemicals), diglycidyl dimeric acid esters (e.g., sold under the trade name Heloxy Modifier 71 from Hexion), and diglycidyl 1,2-cyclohexanedicarboxylate esters (e.g., sold under the trade name Epalloy 5200 from CVC Specialty Chemicals).

[0226] In at least one X group is -Si(R) g ) 3-v (R h ) v In the case of a functional group, the compound of general formula (VII) is an epoxy silane. In a preferred embodiment of the coating composition according to the invention, the epoxy-functionalized compound of general formula (VII) is an epoxy silane. Therefore, X in general formula (VI) is preferably *-Si(R) g ) 3-v (R h ) v Group, where v is 0 or 1, R g It is an alkoxy group containing 1-4 carbon atoms and R h It is an alkoxy group containing one carbon atom or an alkyl group containing one carbon atom.

[0227] Particularly preferred epoxy compounds of general formula (VII) are selected from (3-glycidoxypropyl)trimethoxysilane, dimethoxy(3-glycidoxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, trimethylolpropane triglycidyl ether, and the reaction products of 2,2-bis(hydroxymethyl)-1,3-propanediol and 2-(chloromethyl)ethylene oxide, with a high preference for the reaction products of (3-glycidoxypropyl)trimethoxysilane, trimethylolpropane triglycidyl ether, and 2,2-bis(hydroxymethyl)-1,3-propanediol and 2-(chloromethyl)ethylene oxide.

[0228] At least one epoxy functional compound of general formula (VII) is preferably present in a total amount of 0-20% by weight, more preferably 2.5-15% by weight, and most preferably 5-10% by weight, based on the solids content of the coating composition in each case.

[0229] Other additives:

[0230] The coating compositions of the present invention may further contain at least one conventional and known coating additive in a typical amount, preferably 0-20% by weight, more preferably 0.005-15% by weight, and particularly 0.01-10% by weight, in each case based on the total weight of the coating composition. The weight percentage ranges mentioned above also apply to the sum of all additives.

[0231] Examples of suitable coating additives are (i) UV absorbers; (ii) light stabilizers, such as HALS compounds, benzotriazoles, or oxalanilides; (iii) rheology modifiers, such as sag control agents (urea crystal modified resins), organic thickeners, and inorganic thickeners; (iv) free radical scavengers; (v) slip additives; (vi) polymerization inhibitors; (vii) defoamers; (viii) wetting agents; (ix) fluorinated compounds; (x) adhesion promoters; (xi) leveling agents; (xii) film-forming aids, such as cellulose derivatives; (xiii) fillers, such as silica, alumina, or zirconium oxide-based nanoparticles; (xiv) flame retardants; and (xv) mixtures thereof.

[0232] Among the above-mentioned additives, the most preferred additives are ultraviolet absorbers, light stabilizers, and leveling agents, which are preferably present in an amount of 0.25-2.5% by weight, respectively, based on the total weight of the coating composition.

[0233] It is possible, but not desirable, for the coating composition to contain a base material other than the silane compound R1, the acid-functionalized polymer P1, and the epoxy-functionalized compound of formula (VII). In the context of this invention and according to DIN EN ISO 4618:2007-03, “base material” refers to the non-volatile component of the coating composition, excluding pigments and fillers. However, hereinafter, the term is used primarily with respect to specific physically curable polymers, optionally also thermocurable, examples of polyurethanes, polyesters, polyethers, polyureas, polyacrylates, polysiloxanes, and / or copolymers of said polymers. In the context of this invention, a copolymer refers to polymer particles formed from different polymers. This explicitly includes polymers covalently bonded to each other and those in which different polymers are bonded to each other by adhesion. The definition also covers combinations of these two types of bonding.

[0234] However, such binders, if present, are preferably included in the coating composition according to the invention in an amount less than 10% by weight, more preferably less than 5% by weight, based on the total weight of the coating composition. The most preferred coating composition of the invention does not contain at least one other binder, particularly hydroxyl-functionalized polysiloxanes and / or alkoxy-functionalized polysiloxanes and / or hydroxyl-functionalized poly(meth)acrylates, i.e., said other binders are present in an amount of 0% by weight based on the total weight of the coating composition. The presence of hydroxyl-functionalized poly(meth)acrylates leads to reduced adhesion, particularly vapor jet adhesion, and also to reduced appearance, particularly short-wave appearance and appearance after exposure to humid conditions, and is therefore undesirable in the present invention.

[0235] The additive may contain a catalyst C3 other than the catalysts C1 and C2 described above. Suitable other catalysts C3 are, for example, bicyclic tertiary amines. The most preferred bicyclic tertiary amines are 1,5-diazabicyclo[4.3.0]non-5-ene (hereinafter referred to as DBN), 1,5-diazabicyclo(4,4.0)decene-5 (hereinafter referred to as DBD), or 1,8-diazabicyclo[5.4.0]undec-7-ene (hereinafter referred to as DBU) and 1,4-diazabicyclo[2.2.2]octane (hereinafter referred to as DABCO). DBU and DBN are preferred. DBU is particularly preferred. These bicyclic tertiary amines can be used alone, or in combination of two or more of them.

[0236] If the other catalysts mentioned above are present, preferably DBU, the weight ratio of catalyst C1 to other catalyst C3 is preferably 1:1-8:1, more preferably 2:1-6:1, most preferably 3:1-5:1, such as 4:1.

[0237] The coating compositions of the present invention can be formulated as colored varnish compositions that, when applied to a substrate, are neither completely transparent and colorless like varnishes nor completely opaque like typical pigment-containing coatings. The colored varnishes are therefore transparent and colored, or translucent and colored. Color can be achieved by adding at least one pigment commonly used in coating compositions. Suitable pigments are, for example, organic and inorganic coloring pigments, effect pigments, and mixtures thereof. Such coloring pigments and effect pigments are known to those skilled in the art and described in, for example... -Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, pp. 176 and 451. The terms “coloring pigment” and “colored pigment” are interchangeable, just as the terms “visual effect pigment” and “effect pigment” are interchangeable. Suitable inorganic coloring pigments are selected from (i) white pigments, such as titanium dioxide, zinc white, colored zinc oxide, zinc sulfide, and zinc barium white; (ii) black pigments, such as iron oxide black, iron manganese black, spinel black, and carbon black; (iii) colored pigments, such as ultramarine green, ultramarine blue, manganese blue, ultramarine violet, manganese violet, red iron oxide, molybdenum chrome red, ultramarine red, brown iron oxide, mixed brown, spinel phase and corundum phase, yellow iron oxide, and bismuth vanadate; (iv) filler pigments, such as silica, quartz powder, alumina, aluminum hydroxide, natural mica, natural and precipitated chalk, barium sulfate, and (vi) mixtures thereof.

[0238] Suitable organic coloring pigments are selected from (i) monoazo pigments, such as CI Pigment Brown 25, CI Pigment Orange 5, 36 and 67, CI Pigment Orange 5, 36 and 67, CI Pigment Red 3, 48:2, 48:3, 48:4, 52:2, 63, 112 and 170, and CI Pigment Yellow 3, 74, 151 and 183; and (ii) diazo pigments, such as CI Pigment Red 144, 166, 214 and 242, CI Pigment Red 144, 166, 214 and 2 42 and CI Pigment Yellow 83; (iii) Anthraquinone pigments, such as CI Pigment Yellow 147 and 177 and CI Pigment Violet 31; (iv) Benzimidazole pigments, such as CI Pigment Orange 64; (v) Quinacridone pigments, such as CI Pigment Orange 48 and 49, CI Pigment Red 122, 202 and 206 and CI Pigment Violet 19; (vi) Quinophthalone pigments, such as CI Pigment Yellow 138; (vii) Pyrrolopyrroledione pigments, such as CI Pigment Orange 71 and 73 and CI Pigment Yellow 83. Red 254, 255, 264, and 270; (viii) dioxazine pigments, such as CI pigments violet 23 and 37; (ix) indanone pigments, such as CI pigment blue 60; (x) isoindoline pigments, such as CI pigment yellow 139 and 185; (xi) isoindolineone pigments, such as CI pigment orange 61 and CI pigment yellow 109 and 110; (xii) metal complex pigments, such as CI pigment yellow 153; (xiii) perinone pigments. (xiv) Perylene pigments, such as CI pigments Black 32, CI pigments Red 149, 178 and 179 and CI pigments Violet 29; (xv) Phthalocyanine pigments, such as CI pigments Violet 29, CI pigments Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6 and 16 and CI pigments Green 7 and 36; (xvi) Aniline Black, such as CI pigment Black 1; (xvii) Azobenzene pigments; and (xviii) mixtures thereof.

[0239] Suitable effect pigments are selected from (i) flake-shaped metallic effect pigments, such as flake aluminum pigments, gold bronze, pyrochrome bronze, and iron oxide-aluminum pigments; (ii) pearlescent pigments, such as metal oxide mica pigments; (iii) flake graphite pigments; (iv) flake iron oxide pigments; (v) multilayer effect pigments composed of PVD films; (vi) liquid crystal polymer pigments; and (vii) mixtures thereof.

[0240] The coloring paint composition preferably contains at least one coloring and / or effect pigment in a total amount of 0.1-10% by weight, preferably 1-4% by weight, based on the total weight of the paint composition.

[0241] If the coating compositions of the present invention are formulated as varnish compositions, they preferably do not contain any coloring and / or effect pigments, i.e., the amount of coloring and / or effect pigments is preferably 0% by weight based on the total weight of the coating composition. However, it is also possible to add fillers and matting agents to adjust the gloss of the varnish material.

[0242] The coating composition of the present invention preferably contains only a substantial amount of crosslinking agent, and very preferably contains no crosslinking agent conventionally used in coating compositions. Therefore, the coating composition preferably contains at least one crosslinking agent and / or tin-containing compound in an amount less than 2% by weight, more preferably 0% by weight, based on the total weight of the coating composition.

[0243] The crosslinking agent preferably contained in only small amounts or not present at all in the coating composition is an amino resin, polyisocyanate, blocked polyisocyanate, polycarbodiimide, photoinitiator, and mixtures thereof. The tin-containing compound preferably excluded is a tin catalyst. A combination of silane compound R1 with a mixture of catalysts C1 and C2 and acid-functionalized polymer P1 produces sufficient crosslinking at low curing temperatures without the use of ecologically undesirable polyisocyanates or melamine resins and tin-containing compounds.

[0244] The coating compositions of the present invention can be single-component or two-component coating compositions. If the coating compositions of the present invention are formulated as single-component compositions, trace amounts of water need to be excluded to avoid crosslinking reactions during storage. Preferably, the coating compositions of the present invention are formulated as two-component coating compositions. The two-component coating composition preferably contains a silane compound R1, optionally diluted with an aprotic solvent, and, if present, an epoxy functional compound of general formula (VII), in a first container, and a catalyst C1, a catalyst C2, an acid-functionalized polymer P1, optionally at least one coating additive, and at least an aprotic solvent in a second container. The components in containers 1 and 2 are then mixed before use, preferably immediately before applying the mixed coating composition to the substrate. The formulation of the coating compositions of the present invention as two-component compositions results in higher storage stability because trace amounts of water do not need to be excluded.

[0245] Method of the present invention:

[0246] The present invention also relates to a method of coating a substrate with the coating composition of the present invention, wherein the coating composition of the present invention is applied to the substrate to form a coating film, and then the coating film is cured.

[0247] According to the first alternative, the substrate (S) is preferably selected from metal substrates, metal substrates coated with cured electrophoretic coatings and / or cured fillers, plastic substrates, and substrates comprising metal and plastic components, with metal substrates being particularly preferred. In the case of metal and plastic substrates or substrates comprising metal and plastic components, the substrate may be pretreated in any conventional manner prior to step (1) of the method of the invention—i.e., cleaning (e.g., mechanical and / or chemical cleaning) and / or being given a known conversion coating (e.g., by phosphating and / or chromating) or surface activation pretreatment (e.g., by flame treatment, plasma treatment, and corona discharge treatment).

[0248] In this regard, the preferred metal substrate (S) is selected from iron, aluminum, copper, zinc, magnesium and their alloys, as well as steel. Preferred substrates are iron and steel substrates, examples of which are typical iron and steel substrates used in the automotive industry. The substrate itself can be of any shape; that is, it can be, for example, a simple metal sheet or a complex component, particularly, for example, a car body and its parts.

[0249] Preferred plastic substrates (S) are essentially substrates comprising or composed of the following components: (i) polar plastics, such as polycarbonate, polyamide, polystyrene, styrene copolymers, polyesters, polyphenylene ethers, and blends of these plastics; (ii) synthetic resins, such as polyurethane RIM, SMC, BMC; and (iii) polyolefin substrates of the polyethylene and polypropylene types with high rubber content, such as PP-EPDM, and surface-activated polyolefin substrates. The plastic may also be fiber-reinforced, particularly using carbon fibers and / or metal fibers.

[0250] As the base material (S), a base material that contains both metal and plastic parts can also be used. Such a base material is, for example, a car body containing plastic components.

[0251] A metal substrate containing a cured electrophoretic coating can be obtained by electrophoretically applying an electrophoretic coating onto a metal substrate (S) and curing the applied material at a temperature of 100-250°C, preferably 140-220°C, for 5-60 minutes, preferably 10-45 minutes. Prior to curing, the material can be flash-evaporated, for example, at 15-35°C for 0.5-30 minutes and / or intermediate-dried, for example, at a temperature preferably 40-90°C for 1-60 minutes. Suitable electrophoretic coatings and their curing methods are described in WO 2017 / 088988 A1, and contain hydroxyl-functionalized polyetheramines as a base and blocked polyisocyanates as crosslinking agents. Prior to applying the electrophoretic coating, a conversion coating, such as a zinc phosphate coating, can be applied to the metal substrate. The film thickness of the cured electrophoretic coating is, for example, 10-40 micrometers, preferably 15-25 micrometers.

[0252] A metal substrate comprising a cured electrophoretic coating and / or cured filler can be obtained by applying a filler composition to a metal substrate (S) optionally containing a cured electrophoretic coating, or to a metal and / or plastic substrate (S) and curing the filler composition at a temperature of 40-100°C, preferably 60-80°C, for 5-60 minutes, preferably 3-8 minutes. Suitable filler compositions are well known to those skilled in the art and are available, for example, from BASF Coatings GmbH under the trademark Glasurit. The film thickness of the cured filler is, for example, 30-100 micrometers, preferably 50-70 micrometers.

[0253] According to the second alternative, the substrate in step (1) is a multilayer coating with defective areas. Such a substrate with defective areas is therefore the original coating (i.e., the multilayer coating) to be repaired or completely recoated. The aforementioned defective areas in the multilayer coating can be repaired by the method described above in this invention. For this purpose, the surface to be repaired in the multilayer coating can be sanded first. Sanding is preferably done by partially sanding or removing the base coat and clear coat, or all of the coatings. Especially in the field of OEM automotive refinish paints, it is generally accepted that only the base coat and clear coat are removed, where, unlike in shop-made refinish paints, defects generally only occur in the base coat and / or clear coat areas, and particularly not in the underlying filler layer areas. If defects are also encountered in the filler layer, such as scratches caused by mechanical action and often extending downwards to the substrate surface (metal or plastic substrate), all coatings present on the substrate must be removed.

[0254] Step (1):

[0255] In step (1) of the method of the present invention, the coating composition of the present invention is applied to a substrate (S). The coating composition is applied to the substrate (S) as follows. The coating composition is applied so that the coating film formed in step (2) is located on the substrate, but not necessarily in direct contact with the substrate. For example, other coatings may be provided between the coating film and the substrate. Preferably, applying the coating composition directly to the substrate (S) in step (1) means that the coating film formed in step (2) is in direct contact with the substrate (S).

[0256] The coating composition of the present invention can be applied by methods known to those skilled in the art for applying liquid coatings, such as dip coating, doctor blade coating, spraying, roller coating, etc. Spraying methods are preferred, such as compressed air spraying (pneumatic application), airless spraying, high-speed rotation, electrostatic spraying (ESTA), optionally combined with thermal spraying, such as hot air (thermal spraying). The coating composition is particularly preferably applied by pneumatic spraying or electrostatic spraying.

[0257] Step (2):

[0258] In step (2) of the method of the present invention, a coating film is formed from the coating composition applied in step (1). The formation of the coating film from the applied coating composition can be achieved, for example, by flash evaporation of the applied coating composition. The term "flash evaporation" should, in principle, be understood to mean the passive or active evaporation of solvent from the coating composition at ambient temperature (i.e., room temperature). Since the coating is still fluid immediately after application and at the start of flash evaporation, it can flow to form a uniform, smooth coating film. Therefore, after the flash evaporation period, a relatively smooth coating film containing less solvent than the applied coating composition is obtained. Although the film is no longer flowable, it remains, for example, soft. In particular, the coating film has not yet been cured as described below.

[0259] The coating formation in step (2) is carried out at a temperature of 20-60°C for a duration of 5-80 minutes, preferably at a temperature of 20-35°C for a duration of 5-70 minutes.

[0260] Step (3):

[0261] In step (3) of the method of the present invention, the coating is cured. The curing of the coating or composition should therefore be understood as the transformation of the film or composition into a service-ready state, in other words, a state in which the substrate having the coating can be transported, stored, and used in its intended manner. The cured coating is therefore no longer soft, but becomes a solid coating, which no longer exhibits any significant change in its properties, such as hardness or adhesion to the substrate, even upon further exposure to the curing conditions described below.

[0262] Curing is generally carried out at a temperature of 10-180°C, for example, particularly 40-90°C, for 5-80 minutes, preferably for a duration of 10-50 minutes. Since the method of the present invention is particularly suitable for repair paint applications, where low-temperature curing conditions are necessary, the curing in step (3) is preferably carried out at a temperature of 20-30°C for 10-70 minutes, preferably for a duration of 20-60 minutes.

[0263] The layer thickness obtained after step (3) is typically 15-80 μm, preferably 20-70 μm or 30-65 μm, such as 40-60 μm.

[0264] Coatings made from the coating compositions of this invention exhibit improved appearance, particularly short-wavelength value, and flexibility compared to coating compositions without acid-functionalized polymer P1 or hydroxyl-functionalized polymers. Furthermore, the curing of the coating compositions can be carried out at low temperatures, making the method of this invention particularly suitable for repair paint applications. The cured coatings exhibit good adhesion, rapid sanding and polishing properties, good appearance, stone chip resistance and moisture resistance, as well as high scratch and solvent resistance. Additionally, thick coatings can be formed without defects or stress. Because it lacks commonly used isocyanate and melamine crosslinking agents and tin catalysts, the method of this invention is environmentally friendly and meets stringent environmental regulations.

[0265] The description of the coating composition of the present invention is applicable to further preferred embodiments of the method of preparing the coated substrate of the present invention.

[0266] The coated substrate of this invention:

[0267] After step (3) of the method of the present invention is completed, the coated substrate of the present invention is obtained.

[0268] Depending on the selected substrate material, the coating composition can be used in a wide range of different applications. Many types of substrates can be coated. The coating compositions of the present invention are therefore ideally suited for use as decorative and protective coating systems, particularly for the bodies or components of vehicles (especially motor vehicles such as motorcycles, buses, trucks, or cars). The substrate preferably comprises multiple layers, as used in automotive painting.

[0269] The coating compositions of the present invention are also suitable for use on indoor and outdoor buildings; on furniture, windows and doors; on plastic molded articles, especially CDs and windows; on small industrial parts, coils, containers and packaging; on white goods; on sheets; on optical components, electrical components and mechanical components; and on hollow glassware and articles for everyday use.

[0270] The description of the coating compositions and methods of the present invention is applicable to further preferred embodiments of the coated substrates according to the present invention.

[0271] This invention features a multi-layer coating:

[0272] Another object of the present invention is a multilayer coating consisting of at least two coatings, wherein at least one coating is formed by a coating composition according to the present invention.

[0273] Typically, a multilayer coating consists of at least two coatings.

[0274] The preferred multilayer coating comprises at least a base coat layer and a clear coat layer. The coating composition of the present invention preferably forms a clear coat layer.

[0275] Even more preferred is a multilayer coating comprising at least one filler coating coated with at least one primer layer, which in turn is coated with at least one varnish layer, the varnish layer preferably being formed from the coating composition of the present invention.

[0276] In particular, but not limited to automotive coatings, multilayer coatings preferably include an electrocoat layer, at least one filler coating on the electrocoat layer, at least one primer layer on the electrocoat layer, and at least one clear coat layer on the primer layer, wherein the clear coat layer is preferably formed from the coating composition of the present invention.

[0277] The multilayer coating can be prepared as described above with respect to the method of the present invention. The applied coatings can be cured separately or at least two coatings can be cured simultaneously. Particularly preferably, at least one primer layer and a clear coat layer are cured simultaneously. The application, drying or flash evaporation, and curing of the multilayer coating can be carried out according to methods known in the art. Suitable electrophoretic coating, filler, and primer compositions are, for example, commercially available. Suitable substrates have been mentioned above with respect to the method of the present invention.

[0278] The descriptions of the coating compositions, methods, and coated substrates of the present invention are applicable to further preferred embodiments of the multilayer coatings of the present invention.

[0279] Substrate coated with multiple layers:

[0280] The final subject of this invention is a substrate coated with the aforementioned multilayer coating.

[0281] The descriptions of the coating compositions, methods, coated substrates, and multilayer coatings of the present invention are applicable to further preferred embodiments of the multilayer coated substrates of the present invention.

[0282] The invention is described in particular by way of the following embodiments:

[0283] Implementation Scheme 1: A coating composition comprising:

[0284] a) at least one silane compound R1 having an isocyanate content of less than 1% and comprising at least one silane group of general formula (I).

[0285] *-NR 1 -X-SiR 2 a (OR 3 ) 3-a (I)

[0286] and optionally at least one silyl group of general formula (II)

[0287] *-N[X-SiR 2 a (OR 3 ) 3-a ] n [X'-SiR 2 b (OR 3 ) 3-b ] m (II)

[0288] in

[0289] X and X' are independently straight-chain and / or branched alkylene or cycloalkylene groups having 1-20 carbon atoms;

[0290] R 1 It is an alkyl group containing 1-10 carbon atoms.

[0291] R 2、 R 3 Each of the alkyl, cycloalkyl, aryl, or aralkyl groups is independently an alkyl, cycloalkyl, aryl, or aralkyl group, and the carbon chain of the alkyl, cycloalkyl, aryl, or aralkyl group may be connected by non-adjacent oxygen, sulfur, or NR. a Group spacers, where R a It is alkyl, cycloalkyl, aryl, or aralkyl.

[0292] m and n are independent values ​​of 0-2, provided that m+n=2 and...

[0293] a and b are independently 0-2;

[0294] b) At least one catalyst of general formula (III) C1

[0295] z[C(R 4 (R) 5 (R) 6 )-(CH2) n -C(=O)-O - M z+ (III)

[0296] in

[0297] R 4 -R 6 Each of the residues is independently hydrogen or an alkyl group containing 1-6 carbon atoms, provided that residue R is present. 4 -R 6 The total number of carbon atoms in it is 3-8;

[0298] z is 1-4; and

[0299] n is 0 or 1-8

[0300] The condition is that,

[0301] If z = 1, then M is selected from Li, K, and Na;

[0302] If z = 2, then M is selected from Zn and Zr;

[0303] If z = 3, then M is selected from Bi and Al;

[0304] If z = 4, then M is selected from Zr and Ti;

[0305] c) At least one metal alkoxide C2;

[0306] d) At least one polymer P1 with an acid value greater than 10 mg KOH / g solid, determined according to DIN EN ISO 2114:2002-06 (Procedure A); and

[0307] e) One or more aprotic organic solvents.

[0308] Implementation Scheme 2: The coating composition according to Implementation Scheme 1 is characterized in that the silane compound R1 has an isocyanate content of less than 0.5%, preferably 0.05-0%.

[0309] Implementation Scheme 3: The coating composition according to Implementation Scheme 1 or 2, characterized in that X and X' in formula (I) and (II) independently represent straight-chain alkylene groups having 1-10, preferably 1-6, more preferably 2-5, and very preferably 3 carbon atoms.

[0310] Implementation Scheme 4: The coating composition according to any one of the foregoing implementation schemes, characterized in that R in general formula (I) 1 It is an alkyl group containing 2-8 carbon atoms, preferably 4-6 carbon atoms, and very preferably 4 carbon atoms.

[0311] Implementation Scheme 5: The coating composition according to any one of the foregoing embodiments, characterized in that R in general formulas (I) and (II) 2 Each represents C1-C independently. 10 Alkyl groups, preferably C1-C6 alkyl groups, and very preferably C1 alkyl groups.

[0312] Implementation Scheme 6: The coating composition according to any of the foregoing embodiments is characterized in that a in formulas (I) and (II) and b in general formula (II) are independently 0.

[0313] Implementation Scheme 7: A coating composition according to any of the foregoing embodiments, characterized in that the silane compound R1 contains 50-100 mol%, preferably 80-100 mol%, more preferably 95-100 mol% of at least one silane group of general formula (I) and 0-50 mol%, preferably 0-20 mol%, more preferably 0-5 mol% of at least one silane group of general formula (II), in each case based on the total amount of silane groups of general formula (I) and (II).

[0314] Implementation Scheme 8: A coating composition according to any one of the foregoing embodiments, characterized in that the silane compound R1 is prepared by reacting at least one polyisocyanate with at least one compound of general formula (Ia).

[0315] HNR 1 -X-SiR 2 a (OR 3 ) 3-a (Ia)

[0316] and optionally react with at least one compound of general formula (IIa) to prepare

[0317] HN[X-SiR 2 a (OR 3 ) 3-a ] n [X'-SiR 2 b (OR 3 ) 3-b ] m (IIa)

[0318] in

[0319] X and X' are independently linear and / or branched alkylene or cycloalkylene groups having 1-20 carbon atoms, preferably linear alkylene groups having 3 carbon atoms.

[0320] R 1 It is an alkyl group containing 1-10 carbon atoms, preferably a straight-chain alkyl group containing 4 carbon atoms.

[0321] R 2 R 3 Each of the alkyl, cycloalkyl, aryl, or aralkyl groups is independently an alkyl, cycloalkyl, aryl, or aralkyl group, and the carbon chain of the alkyl, cycloalkyl, aryl, or aralkyl group may be connected by non-adjacent oxygen, sulfur, or NR. a Group spacers, where R a It is an alkyl, cycloalkyl, aryl, or aralkyl group, preferably a C1 alkyl group.

[0322] n and m are independent values ​​of 0-2, provided that m+n=2.

[0323] a and b are independent values ​​of 0-2, with 0 being the preferred value.

[0324] Implementation Scheme 9: The coating composition according to Implementation Scheme 8, characterized in that the at least one polyisocyanate has an average isocyanate functionality of 2-6, preferably 2-5, very preferably 2-3.5.

[0325] Implementation Scheme 10: The coating composition according to Implementation Scheme 8 or 9, characterized in that the polyisocyanate is selected from hexamethylene diisocyanate diketone, hexamethylene diisocyanate, 1-isocyanate-4-[(4-isocyanate-cyclohexyl)methyl]-cyclohexane and hexamethylene diisocyanate trimer.

[0326] Implementation Scheme 11: A coating composition according to any of the foregoing embodiments, characterized in that the silane compound R1 is present in a total amount of 5-45% by weight, more preferably 10-40% by weight, and most preferably 12-35% by weight, based on the total weight of the coating composition in each case.

[0327] Implementation Scheme 12: The coating composition according to any one of the foregoing embodiments, characterized in that residue R in general formula (III) 4 -R 6 The total number of carbon atoms in it is 3-5 or 5-8.

[0328] Implementation Scheme 13: The coating composition according to any of the foregoing embodiments is characterized in that z in general formula (III) is 1, 3 or 4, preferably 1 or 4.

[0329] Implementation Scheme 14: The coating composition according to any of the foregoing implementation schemes is characterized in that n in general formula (III) is 0 or 2-6, preferably 0 or 4.

[0330] Implementation Scheme 15: A coating composition according to any of the foregoing embodiments, characterized in that n in general formula (III) is 0, and residue R 4 and R 5 Each is independently a straight-chain or branched C3-C5 alkyl group, and residue R 6 It is a methyl group, provided that the residue R is present. 4 -R 6 The sum of all carbon atoms is 8.

[0331] Implementation Scheme 16: A coating composition according to any one of Implementation Schemes 1-14, characterized in that n in general formula (III) is 1-8, preferably 4, and residue R 4 -R 6 Each is a methyl group, independent of the others.

[0332] Implementation Scheme 17: The coating composition according to any of the foregoing embodiments is characterized in that M in general formula (III) is potassium, lithium or titanium, preferably potassium or titanium.

[0333] Implementation Scheme 18: The coating composition according to any of the foregoing embodiments is characterized in that the catalyst C1 of at least one general formula (III) is a potassium, lithium or titanium neodecanoate and / or ethylhexanoate, preferably potassium neodecanoate (I), titanium neodecanoate (IV), potassium 2-ethylhexanoate (I) or titanium 2-ethylhexanoate (IV).

[0334] Implementation Scheme 19: The coating composition according to any of the foregoing embodiments is characterized in that the at least one catalyst C1 is present in a total amount of 1-50 mmol, preferably 5-40 mmol, very preferably 15-25 mmol metal / 100g silane compound R1 or R2 solid.

[0335] Implementation Scheme 20: A coating composition according to any one of the foregoing embodiments, characterized in that the at least one metal alkoxide C2 is selected from metal alkoxides of general formula (IV).

[0336] M 1 [(OR 7 ) m (R 8 ) n-m ] n (IV)

[0337] in

[0338] R 7 Is it a straight-chain or branched C1-C? 10 alkyl,

[0339] R 8 It is a halogen group, an acetylacetone group, an alkyl acetoacetate group, or an ethanolamine group, M 1 It represents at least one metal selected from silicon, titanium, tantalum, zirconium, boron, aluminum, magnesium, or zinc.

[0340] m is an integer between 0 and 4, and

[0341] n represents M 1 Its valence is 2-5.

[0342] Implementation Scheme 21: The coating composition according to Implementation Scheme 20, characterized in that R in general formula (IV) 7 Selected from C3-C5 alkyl groups, preferably C3 or C4 alkyl groups and / or R in general formula (IV). 7 It is selected from alkyl acetoacetate groups, preferably from ethyl acetoacetate groups.

[0343] Implementation Scheme 22: The coating composition according to Implementation Scheme 20 or 21 is characterized in that m in general formula (IV) is 0 or 1-4, more preferably 0 or 2-4, and very preferably 0, 2 or 4.

[0344] Implementation Scheme 23: A coating composition according to any one of Implementation Schemes 20-22, characterized in that M in general formula (IV) 1 It is a metal selected from titanium, and n represents the valence of 4.

[0345] Implementation Scheme 24: The coating composition according to any of the foregoing embodiments is characterized in that the metal alkoxide C2 is selected from titanium isopropoxide (IV) and / or titanium n-butoxide (IV) and / or bis(ethyl acetoacetate) diisopropoxide (IV), with titanium isopropoxide (IV) being the most preferred.

[0346] Implementation Scheme 25: A coating composition according to any of the foregoing embodiments, characterized in that the at least one metal alkoxide C2, preferably a metal alkoxide of general formula (IV), is present in a total amount of 2.5-40 millimoles of metal, in each case based on 100 grams of silane compound R1 solid.

[0347] Implementation Scheme 26: The coating composition according to any of the foregoing embodiments is characterized in that the metal / metal ratio of the catalyst C1 of general formula (III) and the at least one metal alkoxide C2, preferably the metal alkoxide of general formula (IV), is 1:2-2:1.

[0348] Implementation Scheme 27: The coating composition according to any one of the foregoing embodiments is characterized in that the at least one polymer P1 is selected from homopolymers or copolymers of unsaturated acids, polyurethanes having at least one group capable of forming anions, polyurethane (meth) acrylates having at least one group capable of forming anions, and mixtures thereof, preferably homopolymers or copolymers of unsaturated acids, and very preferably homopolymers or copolymers of unsaturated carboxylic acids.

[0349] Implementation Scheme 28: The coating composition according to Implementation Scheme 27 is characterized in that the at least one anion-forming group is selected from carboxylic acid groups, sulfonic acid groups, phosphonic acid groups and mixtures thereof, preferably carboxylic acid groups.

[0350] Implementation Scheme 29: The coating composition according to any of the foregoing embodiments is characterized in that the neutralization degree of the at least one polymer P1 is 0-20%, more preferably 0-10%, and very preferably 0%.

[0351] Implementation Scheme 30: The coating composition according to any one of the foregoing embodiments, characterized in that the at least one polymer P1 comprises, in polymeric form:

[0352] (i) at least one unsaturated monomer M1 having at least one group capable of forming an anion;

[0353] (ii) Optionally, at least one unsaturated monomer M2 selected from esters of (meth)acrylic acid having at least one alkyl group substituted with a hydroxyl group;

[0354] (iii) Optionally, at least one other unsaturated monomer M3 different from monomers M1 and M2; and

[0355] (iv) Optionally at least one lactone;

[0356] (v) Optionally at least one cyclic carboxylic anhydride.

[0357] Implementation Scheme 31: The coating composition according to Implementation Scheme 30 is characterized in that the at least one monomer M1 is selected from (meth)acrylic acid, ethylacrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid; olefinic unsaturated sulfonic acids and phosphonic acids and their esters; and mono(meth)acryloyloxyethyl maleate, mono(meth)acryloyloxyethyl succinate and mono(meth)acryloyloxyethyl phthalate, preferably (meth)acrylic acid, very preferably acrylic acid.

[0358] Implementation Scheme 32: The coating composition according to Implementation Scheme 30 or 31 is characterized in that the at least one monomer M1, in particular acrylic acid, is present in a total amount based on compounds (i) to (v) preferably in the amount of 1-100% by weight, preferably 5-50% by weight, more preferably 10-20% by weight, and very preferably 12-17% by weight.

[0359] Implementation Scheme 33: A coating composition according to any one of Implementation Schemes 30-32, characterized in that the at least one unsaturated monomer M2 is selected from 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate and mixtures thereof, with 2-hydroxyethyl methacrylate being particularly preferred.

[0360] Implementation Scheme 34: A coating composition according to any one of Implementation Schemes 30-33, characterized in that the at least one monomer M2, in particular 2-hydroxyethyl methacrylate, is present in a total amount of 1-30% by weight, preferably 5-25% by weight, more preferably 10-20% by weight, and very preferably 12-15% by weight, based on the total amount of compounds (i) to (v).

[0361] Implementation Scheme 35: A coating composition according to any one of Implementation Schemes 30-34, characterized in that the polymer P1 comprises at least one other monomer M3, the total amount of which in each case is 1-75% by weight, preferably 5-70% by weight, more preferably 10-65% by weight, and very preferably 50-60% by weight, based on the total amount of compounds (i) to (v).

[0362] Implementation Scheme 36: A coating composition according to any one of Implementation Schemes 30-35, characterized in that the at least one monomer M3 is selected from alkyl (meth)acrylate (M3-1) and / or an unsaturated monomer (M3-2) having at least one aromatic structural moiety.

[0363] Implementation Scheme 37: The coating composition according to Implementation Scheme 36 is characterized in that the (meth)acrylate alkyl ester (M3-1) is selected from (meth)acrylate methyl ester, (meth)acrylate ethyl ester, (meth)acrylate propyl ester, (meth)acrylate isopropyl ester, (meth)acrylate n-butyl ester, (meth)acrylate isobutyl ester, (meth)acrylate tert-butyl ester, (meth)acrylate pentyl ester, (meth)acrylate hexyl ester, (meth)acrylate n-butylmethyl ester, (meth)acrylate ethylhexyl ester, (meth)acrylate 3,3,5-trimethylhexyl ester, (meth)acrylate stearyl ester, (meth)acrylate lauryl ester, (meth)acrylate cycloalkyl esters such as (meth)acrylate cyclopentyl ester, (meth)acrylate isobornyl ester, (meth)acrylate cyclohexyl ester and mixtures thereof, preferably n-butylmethyl ester and / or ethylhexyl ester.

[0364] Implementation Scheme 38: The coating composition according to Implementation Scheme 36 or 37 is characterized in that the unsaturated monomer (M3-2) containing at least one aromatic group is selected from vinyl aromatic compounds, such as styrene, α-methylstyrene, vinyltoluene, tert-butylstyrene and mixtures thereof, preferably styrene.

[0365] Implementation Scheme 39: A coating composition according to any one of Implementation Schemes 36-38, characterized in that alkyl (meth)acrylate (M3-1), particularly n-butyl methyl acrylate and / or ethylhexyl acrylate, are present in polymer P1 in a total amount of 10-60% by weight, preferably 30-55% by weight, more preferably 35-50% by weight, and very preferably 37-46% by weight, based on the total amount of compounds (i) to (v).

[0366] Implementation Scheme 40: A coating composition according to any one of Implementation Schemes 36-39, characterized in that an unsaturated monomer (M3-2) comprising at least one aromatic group is present in polymer P1 in a total amount of 1-30% by weight, preferably 5-25% by weight, more preferably 10-20% by weight, and very preferably 14-17% by weight based on the total amount of compounds (i) to (v) in each case.

[0367] Implementation Scheme 41: A coating composition according to any one of Implementation Schemes 36-40, characterized in that polymer P1 contains an alkyl methacrylate (M3-1) in a weight ratio of 5:1 to 1:1, more preferably 4:1 to 1:1, and very preferably 3:1 to 2:1, and an unsaturated monomer (M3-2) comprising at least one aromatic structural moiety.

[0368] Implementation Scheme 42: A coating composition according to any one of Implementation Schemes 30-41, characterized in that the at least one lactone is selected from compounds of general formula (V):

[0369]

[0370] in

[0371] p is an integer from 1 to 10, preferably from 1 to 8, more preferably from 3 to 6, and most preferably from 5.

[0372] Implementation Scheme 43: A coating composition according to any one of Implementation Schemes 30-42, characterized in that the at least one lactone, particularly ε-caprolactone, is used in a total amount based on compounds (i) to (v) preferably in the amount of 0.5-25% by weight, more preferably 1-20% by weight, more preferably 5-15% by weight, and very preferably 5-11% by weight.

[0373] Implementation Scheme 44: A coating composition according to any one of Implementation Schemes 30-43, characterized in that the cyclic carboxylic anhydride is selected from aromatic and aliphatic carboxylic anhydrides, preferably aliphatic carboxylic anhydrides, and very preferably hexahydrophthalic anhydride.

[0374] Implementation Scheme 45: A coating composition according to any one of Implementation Schemes 30-44, characterized in that the polymer P1 contains at least one cyclic carboxylic anhydride, preferably hexahydrophthalic anhydride, the total amount of which in each case is 1-30% by weight, more preferably 5-25% by weight, even more preferably 8-15% by weight, and very preferably 5-11% by weight, based on the total amount of compounds (i) to (v).

[0375] Implementation Scheme 46: The coating composition according to any one of the foregoing embodiments is characterized in that the acid value of the at least one polymer P1 is 15-400 mg KOH / g solids, preferably 30-300 mg KOH / g solids, more preferably 60-200 mg KOH / g solids, and very preferably 90-130 mg KOH / g solids, as determined according to DIN EN ISO 2114:2002-06 (Procedure A).

[0376] Implementation Scheme 47: The coating composition according to any of the foregoing embodiments, characterized in that the weight-average molecular weight Mw of the at least one polymer P1 is 1,000-10,000 g / mol, preferably 3,000-8,000 g / mol, more preferably 4,000-6,000 g / mol, and very preferably 4,800-5,400 g / mol, as determined according to DIN 55672-1:2016-03.

[0377] Implementation Scheme 48: The coating composition according to any of the foregoing embodiments is characterized in that the polydispersity D (Mw / Mn) of the at least one polymer P1 is 2.0-6.5, preferably 3.0-6.0, and very preferably 4.3-4.8.

[0378] Implementation Scheme 49: A coating composition according to any one of the foregoing embodiments, characterized in that the at least one polymer P1 is obtained by the following

[0379] (a) Polymerize a mixture M comprising the following components:

[0380] (i) at least one unsaturated monomer M1 having at least one group capable of forming an anion;

[0381] (ii) Optionally, at least one unsaturated monomer M2 selected from esters of (meth)acrylic acid having at least one alkyl group substituted with a hydroxyl group;

[0382] (iii) Optionally, at least one monomer M3 that is different from monomers M1 and M2;

[0383] (iv) optionally at least one lactone; and

[0384] (b) Optionally, the polymer obtained in step (a) is reacted with at least one cyclic carboxylic anhydride.

[0385] Implementation Scheme 50: The coating composition according to Implementation Scheme 49 is characterized in that the at least one unsaturated monomer M1 having at least one group capable of forming an anion, particularly acrylic acid, is present in the mixture M in a total amount of 5-35% by weight, more preferably 7-30% by weight, even more preferably 10-25% by weight, and very preferably 12-19% by weight.

[0386] Implementation Scheme 51: The coating composition according to Implementation Scheme 49 or 50 is characterized in that the at least one unsaturated monomer M2, in particular 2-hydroxyethyl methacrylate, is used in a total amount of 5-30% by weight, more preferably 7-25% by weight, even more preferably 10-20% by weight, and very preferably 12-18% by weight based on the total amount of mixture M.

[0387] Implementation Scheme 52: A coating composition according to any one of Implementation Schemes 49-51, characterized in that at least one unsaturated monomer M3, different from monomers M1 and M2, particularly n-butyl methyl acrylate and / or ethylhexyl acrylate and / or styrene, is present in a total amount of 40-80% by weight, more preferably 45-75% by weight, even more preferably 50-70% by weight, and very preferably 57-65% by weight, based on the total amount of mixture M.

[0388] Implementation Scheme 53: A coating composition according to any one of Implementation Schemes 49-52, characterized in that the at least one lactone, particularly ε-caprolactone, is used in a total amount of 1-30% by weight, more preferably 3-25% by weight, even more preferably 4-20% by weight, and very preferably 5-13% by weight, based on the total amount of mixture M.

[0389] Implementation Scheme 54: A coating composition according to any one of Implementation Schemes 49-53, characterized in that, in each case, a total amount of 1-30% by weight, more preferably 5-25% by weight, even more preferably 8-20% by weight, and very preferably 10-15% by weight of a cyclic carboxylic anhydride, preferably hexahydrophthalic anhydride, is reacted with the polymer obtained in step (a).

[0390] Embodiment 55: A coating composition according to any of the foregoing embodiments, characterized in that the at least one polymer P1 is present in a total amount of 0.1-15% by weight, more preferably 0.5-10% by weight, and most preferably 1.5-8% by weight based on the total weight of the coating composition in each case.

[0391] Implementation Scheme 55: The coating composition according to any of the foregoing embodiments is characterized in that the at least one aprotic solvent is selected from aliphatic and / or aromatic hydrocarbons, ketones, esters, ethers or mixtures thereof, preferably esters, and very preferably butyl acetate.

[0392] Implementation Scheme 56: A coating composition according to any of the foregoing embodiments, characterized in that the coating composition contains less than 10% by weight, preferably less than 5% by weight, more preferably less than 1% by weight, and very preferably 0% by weight of water and / or proton solvent, in each case based on the total weight of the coating composition.

[0393] Implementation Scheme 57: A coating composition according to any of the foregoing embodiments, characterized in that the at least one aprotic solvent is present in a total amount of 1-70% by weight, more preferably 20-60% by weight, and most preferably 30-50% by weight, based on the total weight of the coating composition in each case.

[0394] Implementation Scheme 58: A coating composition according to any of the foregoing embodiments, characterized in that it further comprises at least one carboxylic acid of general formula (VI).

[0395] C(R 4 (R) 5 (R) 6 )-(CH2) n -C(=O)-OH (VI)

[0396] in

[0397] R 4 -R 6 Each of the residues is independently hydrogen or an alkyl group containing 1-6 carbon atoms, provided that residue R is present. 4 and R 6 The total number of carbon atoms in the sample is 3-8, preferably 5-8; and

[0398] n is 0 or 1-8, preferably 0 or 4.

[0399] Implementation Scheme 59: The coating composition according to Implementation Scheme 58 is characterized in that the at least one carboxylic acid of general formula (VI) is neodecanoic acid.

[0400] Implementation Scheme 60: A coating composition according to Implementation Scheme 58 or 59, characterized in that at least one carboxylic acid of general formula (VI), preferably neodecanoic acid, is present in a total amount of 0-80% by weight, preferably 30-70% by weight, very preferably 50-60% by weight, in each case based on the total amount of catalyst C1 of general formula (III).

[0401] Implementation Scheme 61: The coating composition according to any one of the foregoing embodiments is characterized in that it further comprises at least one epoxy functional compound of general formula (VII).

[0402] (X) n -R 9 -Ox (VII)

[0403] in

[0404] Ox is an ethylene oxide group;

[0405] R 9 It is an aliphatic hydrocarbon group containing 2-15 carbon atoms and optionally including an ether group and / or an ester group;

[0406] n is 1-5; and

[0407] X is either Ox or *-Si(R) independently of each other. g ) 3-v (R h ) v Group, where v is 0 or 1, R g It is an alkoxy group containing 1-4 carbon atoms, and R h It is an alkyl group containing 1-4 carbon atoms or an alkoxy group containing 1-4 carbon atoms.

[0408] Implementation Scheme 62: The coating composition according to Implementation Scheme 61, characterized in that R in general formula (VII) 9 It is an aliphatic hydrocarbon group *-(CH2)3-O-CH2- # Or cyclohexylethyl.

[0409] Implementation Scheme 63: The coating composition according to Implementation Scheme 61 or 62 is characterized in that n in general formula (VII) is 1.

[0410] Implementation Scheme 64: A coating composition according to any one of Implementation Schemes 61-63, characterized in that X in general formula (VII) is *-Si(R g ) 3-v (R h ) v Group, where v is 0 or 1, R g It is an alkoxy group containing 1-4 carbon atoms and R h It is an alkoxy group containing one carbon atom or an alkyl group containing one carbon atom.

[0411] Implementation Scheme 65: A coating composition according to any one of Implementation Schemes 61-64, characterized in that the at least one epoxy compound of general formula (VII) is selected from (3-glycidoxypropyl)trimethoxysilane, dimethoxy(3-glycidoxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, trimethylolpropane triglycidyl ether, and the reaction product of 2,2-bis(hydroxymethyl)-1,3-propanediol and 2-(chloromethyl)ethylene oxide, preferably the reaction product of (3-glycidoxypropyl)trimethoxysilane, trimethylolpropane triglycidyl ether, and 2,2-bis(hydroxymethyl)-1,3-propanediol and 2-(chloromethyl)ethylene oxide.

[0412] Implementation Scheme 66: A coating composition according to any one of Implementation Schemes 61-65, characterized in that the at least one epoxy functional compound of general formula (VII) is present in a total amount of 0-20% by weight, more preferably 2.5-15% by weight, and most preferably 5-10% by weight, based on the solids content of the coating composition in each case.

[0413] Implementation Scheme 67: A coating composition according to any of the foregoing embodiments, characterized in that the coating composition further comprises at least one catalyst C3 different from catalysts C1 and C2, wherein catalyst C3 is preferably selected from bicyclic tertiary amines, and very preferably selected from DBU.

[0414] Implementation Scheme 68: The coating composition according to Implementation Scheme 67 is characterized in that the coating composition contains catalyst C1 and other catalyst C3 in a weight ratio preferably 1:1-8:1, more preferably 2:1-6:1, most preferably 3:1-5:1, such as 4:1.

[0415] Implementation Scheme 69: A coating composition according to any of the foregoing embodiments, characterized in that the coating composition comprises at least one base material B other than silane compound R1 and polymer P1, the total amount of which is 0% by weight based on the total weight of the coating composition.

[0416] Implementation Scheme 70: A coating composition according to any of the foregoing implementation schemes, characterized in that it is a varnish composition or a colored varnish composition.

[0417] Implementation Scheme 71: A coating composition according to any of the foregoing embodiments, characterized in that the coating composition comprises at least one crosslinking agent and / or tin-containing compound in an amount of less than 2% by weight, preferably 0% by weight, based on the total weight of the coating composition.

[0418] Implementation Scheme 72: The coating composition according to Implementation Scheme 71 is characterized in that the crosslinking agent is selected from amino resins, polyisocyanates, blocked polyisocyanates, polycarbodiimides, photoinitiators and mixtures thereof.

[0419] Implementation Scheme 73: A coating composition according to any of the foregoing embodiments, characterized in that it is a two-component coating composition, preferably containing a silane compound R1 and, if present, an epoxy functional compound of general formula (VII) in a first container, and containing a catalyst C1, a catalyst C2, at least one polymer P1, optionally a catalyst C3, optionally at least one coating additive and at least an aprotic solvent in a second container.

[0420] Implementation Scheme 74: A method for forming a coating on a substrate (S), comprising the following steps:

[0421] (1) Applying a coating composition of any one of embodiments 1-73 to a substrate (S);

[0422] (2) A coating film is formed from the coating composition applied in step (1); and

[0423] (3) Curing the coating film formed in step (2).

[0424] Implementation Scheme 75: The method according to Implementation Scheme 74 is characterized in that the substrate (S) is selected from metal substrates, metal substrates coated with cured electrophoretic coatings and / or cured fillers, plastic substrates and substrates containing metal and plastic components, and is particularly preferred to be selected from metal substrates.

[0425] Implementation Scheme 76: The method according to Implementation Scheme 75 is characterized in that the metal substrate is selected from the group consisting of or composed of the following: iron, aluminum, copper, zinc, magnesium and their alloys, and steel.

[0426] Implementation Scheme 77: The method according to Implementation Scheme 74 is characterized in that the substrate in step (1) is a multilayer coating with defective parts.

[0427] Implementation Scheme 78: The method according to any one of Implementation Schemes 74-77 is characterized in that the coating formation in step (2) is carried out at a temperature of 20-60°C for a duration of 5-80 minutes, preferably at a temperature of 20-35°C for a duration of 5-70 minutes.

[0428] Implementation Scheme 79: The method according to any one of Implementation Schemes 74-78 is characterized in that the curing in step (3) is carried out at a temperature of 20-30°C for 10-70 minutes, preferably for a duration of 20-60 minutes.

[0429] Implementation Scheme 80: Coated substrate obtained by any one of Implementation Schemes 74-79.

[0430] Implementation Scheme 81: A multilayer coating comprising at least two coatings, wherein at least one coating is formed from a coating composition according to any one of Implementation Schemes 1-73.

[0431] Implementation Scheme 82: A substrate coated with a multilayer coating as described in Implementation Scheme 81. Example

[0432] The invention will now be explained in more detail by way of working embodiments, but the invention is by no means limited to these working embodiments. Furthermore, unless otherwise indicated, the terms “parts,” “%,” and “ratio” in the embodiments refer to “parts by mass,” “% by mass,” and “mass ratio,” respectively.

[0433] 1. Measurement method:

[0434] 1.1 Solid content (solids, non-volatile matter)

[0435] Non-volatile matter was determined according to DIN EN ISO 3251 (dated June 2008). This involves weighing 1 gram of sample into a pre-dried aluminum pan, drying it in a drying oven at 130°C for 60 minutes, cooling it in a desiccator, and then weighing it again. The residue relative to the total amount of sample used corresponds to the non-volatile matter.

[0436] 1.2 Isocyanate content (NCO content)

[0437] The isocyanate content was determined by back-titering the excess amine with 0.1N hydrochloric acid potentiometrically using methods based on DIN EN ISO 3251:2008-06, DIN EN ISO 11909:2007-05, and DIN EN ISO 14896:2009-07, in a homogeneous solution of the sample in acetone / N-ethylpyrrolidone (1:1 vol%). The NCO content of the silane compound R based on the solids content can be calculated using the polymer proportion (solids content) in the solution.

[0438] 1.3 Weight-average and number-average molecular weight M w M n

[0439] Weight-average molecular weight M w and number-average molecular weight M n Determined according to GPC and DIN 55672-1:2016-03 using polystyrene as an internal standard.

[0440] 1.4 Acid value

[0441] The acid value of polymer P1 was determined according to DIN EN ISO 2114:2002-06 (Procedure A).

[0442] 1.5 Preparation of Multilayer Coatings (MC)

[0443] First use R-zinc phosphate (available from Chemetall GmbH) pre-treats the steel sheet, followed by coating with ED coating (Cathogard 800, available from BASF Coatings GmbH) at a dry film thickness of 17-25 μm.

[0444] Subsequently, the electrodeposited plate was coated using a pneumatic spray gun at a temperature of 25°C and a relative humidity of 65%, as described below. A primer (Glasurit 285-270, BASF Coatings GmbH) was applied to the electrodeposited plate to achieve a film thickness of 50-70 μm after curing at 60°C. The primer was then sanded and a commercially available water-based primer (Glasurit Line 90-1250 Deep Black, BASF Coatings GmbH) was applied to achieve a film thickness of 10-20 μm after flash drying until touch dry for approximately 30 minutes. In the final step, the corresponding varnish compositions C-C1 to C-C4 and C-I1 to C-I3 described in Table 1 below were applied over the undercoat and allowed to cure under ambient conditions until touch dry for approximately 15 to 75 minutes. The dry film thickness of the varnish layer was 35-80 μm. Two plates were prepared as described above for each of the varnishes C-C1 to C-C4 and C-I1 to C-I3.

[0445] 1.6 Test Measurement

[0446] 1.6.1 Surface drying time

[0447] Surface drying time is determined by the Guillotine test according to DIN EN ISO 9117-5:2012-11. For this test, 1.5 grams of sea sand is poured onto the varnish layer. Excess sand is poured off the board. The board is then transferred to a device (Guillotine) that guides the board to fall from 30 cm above the surface in a self-drop manner. The board lands on the surface with its edge intact, and any remaining sand particles are then examined. If no sand particles are left on the coated surface, the Guillotine test is considered OK and the coating is "surface dry".

[0448] 1.6.2 Xylene Test

[0449] Seven days after preparing the multilayer coating as described above, apply a large drop (approximately 2 ml) of xylene to the coating and remove it after 4 minutes. One hour later, clean the surface with PK700 cleaner (available from RM Automotive Refinish Paints) and inspect the coating. Measure the visibility of the droplet edge on a scale of 0 to 5 (where 0 indicates no visible ring and 5 indicates complete removal of the clear coat).

[0450] 1.6.3 Adhesion by Cross-Strike Test

[0451] The cross-cut adhesion test was performed according to DIN EN ISO 2409:2013-06 after 7 days of preparing the multilayer coating as described above and after exposing the multilayer coating to 40°C and 100% humidity for 240 hours. 1.6.4 Stone Chip

[0452] The adhesion test and evaluation of the crushed stone were conducted in accordance with DIN EN ISO 20567-1:2017-07 and DIN 55996-1:2001-04.

[0453] 1.6.5 Steam jet adhesion

[0454] Steam jet adhesion was tested according to DIN 55662:2009-12.

[0455] 1.6.6 Visual evaluation of blistering, whitening, cracking, swelling and delamination after wet exposure

[0456] Seven days after the preparation of the multilayer coating, the corresponding plates were transferred to a climate chamber at 40°C and 100% humidity for 240 hours. Afterward, blistering and whitening were visually inspected according to DIN EN ISO 4628-2:2016-07. Cracks, swelling, and delamination were also visually evaluated. If no cracks, swelling, or delamination were detected, the rating for each standard was “NO”. Otherwise, the rating was “YES”.

[0457] 1.6.7 Appearance evaluation (measurement of DOI, du, long-wavelength (LW) and short-wavelength (SW))

[0458] Appearance measurements were performed using the "Wavescan Dual" device from BYK, which is based on laser measurements at an incident angle of 60°. The device was moved across the surface, and the results were recorded depending on the dimensions of the structure. For this purpose, SW values ​​refer to structures ranging from 0.3 to 1.2 mm, and LW values ​​refer to structures ranging from 1.2 to 12 mm. Detailed descriptions of the equipment used, measurement methods, and length dimensions of the structures being treated can be found in the following literature: BYK-Gardner Instrumente, "Qualitatskontrolle fur Lacke", 2008, Glanz / Appearance, available from BYK Gardner, Lausitzer Strasse 8, 82538 Geretsried, Germany.

[0459] 1.6.8 Gloss and Haze Measurement

[0460] Gloss and haze were measured using a Byk Gardener micro-haze plus photometer operating according to DIN 67 530, ISO 2813, ASTM D 523 and ASTM E 430.

[0461] 1.6.9 Micropenetration (Martens Hardness)

[0462] Microneedle penetration or Martens hardness was determined according to DIN EN ISO 14577-4:2017-04 (German version).

[0463] 1.6.10 Erichsen Depth

[0464] Erichsen depth was determined according to DIN EN ISO 1520:2007-11 (German version).

[0465] 2. Preparation of silane compound R

[0466] Silyl compound R was prepared by reacting 25.52 g of 4,4′-methylenebis(cyclohexyl isocyanate, Desmodur W) with 2 equivalents of N-(n-butyl)-3-aminopropyltrimethoxysilane (44.48 g) in 20 g of butyl acetate and 10 g of ethyl methyl ketone at 60 °C until the remaining NCO content reached 0%.

[0467] 3. Preparation of polymers P1-1 to P1-3 with different acid functionalizations

[0468] Different acid-functionalized polymers P1, each having an acid value greater than 10 mg KOH / g solid, were prepared according to the general procedure listed in Table 1 below:

[0469] An initiator solution prepared by mixing an appropriate amount of tert-butyl per-2-ethylhexanoate in 10 g of solvent naphtha was added over 5 hours, and a monomer mixture M containing an appropriate amount of monomer and optionally ε-caprolactone was added to a reactor vessel at 150°C over 4 hours. The addition of monomer mixture M began 15 minutes after the addition of the initiator solution. After the addition of the initiator solution and monomer mixture M was complete, the temperature was lowered to 102°C and an appropriate amount of molten hexahydrophthalic anhydride was added. Thereafter, the temperature was increased to 120°C and the reaction was carried out until an acid value of 120–140 mg KOH / g solid was obtained.

[0470] The properties of the obtained acid-functionalized polymers P1-1 to P1-5 are listed in Table 2.

[0471] Table 1: Amounts used to prepare different acid-functionalized polymers P1 (all amounts given in grams)

[0472]

[0473]

[0474] Table 2: Properties of the obtained acid-functionalized polymers P1-1 to P1-5

[0475]

[0476] 4. Preparation of varnish compositions C-C1 to C-C4 and C-I1 to C-I13

[0477] The components of the comparative coating compositions C-C1 to C-C4 and the components of the coating compositions C-I1 to C-I13 of the present invention were mixed in the amounts shown in Table 3. Component I was mixed first, followed by the addition of premixed component II. All amounts are in grams. All varnish compositions have a non-volatile content of 55.0%.

[0478] Table 3: Formulations of different varnish compositions

[0479]

[0480]

[0481] *This invention

[0482] **NVC = Non-volatile matter content**

[0483] 1) Prepared by free radical polymerization of a monomer mixture containing 20 wt% styrene, 15 wt% n-butyl methacrylate, 20 wt% hydroxypropyl methacrylate, 18 wt% 2-hydroxyethyl methacrylate, 1 wt% acrylic acid, and 26 wt% cyclohexyl methacrylate (OH value (calculated: 152-160 mg KOH / g solid, acid value: 8-10 mg KOH / g solid)).

[0484] 2) Potassium neodecanoate (containing 56% by weight of neodecanoic acid based on catalyst C1)

[0485] 3) Metal alkoxides of general formula (IV), wherein R 7 = Branched C3 alkyl groups, m=4, n=4 and M 1 =Ti (Titanium content: 29.7%)

[0486] 4) Polyether-modified polydimethylsiloxane (leveling additive, supplied by BYK Chemie GmbH)

[0487] 5) HALS (supplied by BASF SE)

[0488] 6) Liquid hydroxyphenyltriazine (HPT) UV absorber (supplied by BASF SE)

[0489] Table 3: Formulations of Different Varnish Compositions - Continued

[0490]

[0491]

[0492]

[0493] *This invention

[0494] **NVC = Non-volatile matter content**

[0495] 1) Prepared by free radical polymerization of a monomer mixture containing 20 wt% styrene, 15 wt% n-butyl methacrylate, 20 wt% hydroxypropyl methacrylate, 18 wt% 2-hydroxyethyl methacrylate, 1 wt% acrylic acid, and 26 wt% cyclohexyl methacrylate (OH value (calculated: 152-160 mg KOH / g solid, acid value: 8-10 mg KOH / g solid)).

[0496] 2) Potassium neodecanoate (containing 56% by weight of neodecanoic acid based on catalyst C1)

[0497] 3) Metal alkoxides of general formula (IV), wherein R 7 = Branched C3 alkyl groups, m=4, n=4 and M 1 =Ti (Titanium content: 29.7%)

[0498] 4) Polyether-modified polydimethylsiloxane (leveling additive, supplied by BYK Chemie GmbH)

[0499] 5) HALS (supplied by BASF SE)

[0500] 6) Liquid hydroxyphenyltriazine (HPT) UV absorber (supplied by BASF SE)

[0501] 5. Results

[0502] The results obtained from the multilayer coatings prepared using varnish compositions C-C1 to C-C4 and C-I1 to C-I13 according to point 1.3 are listed in Tables 4-7.

[0503] Table 4: Results of performance of multilayer coatings MC1 to MC17 (The upper part of this table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments)

[0504]

[0505]

[0506] *This invention

[0507] Table 4: Performance Results of Multilayer Coatings MC1 to MC17 (The upper part of this table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments) - Continued

[0508]

[0509]

[0510] *This invention

[0511] Table 5: Visual inspection results of multilayer coatings MC1' to MC17' after removal of the corresponding plates from the constant climate chamber (the upper part of this table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments).

[0512]

[0513] *This invention

[0514] Table 5: Visual inspection results of multilayer coatings MC1' to MC17' after removal of the corresponding plates from the constant climate chamber (the upper part of this table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments) - Continued

[0515]

[0516]

[0517] *This invention

[0518] Table 6: Results of multilayer coatings MC1 to MC17 in terms of various appearance parameters (the upper part of the table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments).

[0519]

[0520] *This invention

[0521] Table 6: Results of multilayer coatings MC1 to MC17 in terms of various appearance parameters (the upper part of this table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments) – Continued

[0522]

[0523]

[0524] *This invention

[0525] Table 7: Results of hardness for multilayer coatings MC1 to MC7 and MC12 to MC17 (the upper part of the table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments).

[0526]

[0527] *This invention

[0528] Table 7: Results of hardness for multilayer coatings MC1 to MC7 and MC12 to MC17 (the upper part of this table only lists the differences in composition between the embodiments of the present invention and the comparative embodiments) – Continued

[0529]

[0530]

[0531] *This invention

[0532] Compared to the comparative multilayer coatings MC-1 to MC-4, the addition of acid-functionalized polymer P1-1, comprising 11% by weight of ε-caprolactone based on compounds (i) to (v), to the coating compositions CI1 to CI3 of the present invention does not negatively affect the stone chip resistance of the resulting multilayer coatings (MC-5 to MC-7). No negative impact on stone chip resistance was observed after the addition of acid-functionalized polymer P1-2, which has a lower ε-caprolactone content compared to acid-functionalized polymer P1-1, or acid-functionalized polymers P1-4 and P1-5, which have a higher ε-caprolactone content but a lower acid value. Increasing the amount of acid-functionalized polymer P1-1 in the varnish compositions (C-I1 to C-I3) of the present invention results in improved vapor jet adhesion and cross-cut adhesion after preparation and after treatment of the multilayer coatings under wet conditions. When the following acid-functional polymers are used in the coating compositions of the present invention C-I4 to CI13 (see Table 4): acid-functional polymer P1-2 containing only 5.9 wt% ε-caprolactone, acid-functional polymer P1-3 without ε-caprolactone, acid-functional polymer P1-4 containing 12.5 wt% ε-caprolactone with an acid value of 95.9 mg KOH / g solids, or acid-functional polymer P1-5 containing 14.0 wt% ε-caprolactone with an acid value of only 61.8 mg KOH / g solids, improved vapor jet adhesion and cross-cut adhesion are obtained after preparation and after treatment of multilayer coatings under humid conditions.

[0533] Compared to the multilayer MC1' prepared from a varnish composition without hydroxyl-functionalized polyacrylate, the addition of a small amount of hydroxyl-functionalized polyacrylate with an acid value of less than 10 mg KOH / g solids to the comparative varnish compositions C-C2 resulted in a reduction in whitening of the resulting multilayer MC-2' under humid conditions. However, the addition of larger amounts of hydroxyl-functionalized polyacrylate (comparative multilayers MC-3' and MC-4') negatively impacted the resulting multilayer coatings, causing blistering, whitening, and delamination. Surprisingly, compared to the comparative multilayer coating MC-1' without hydroxyl and acid-functionalized polymers and the comparative multilayer coatings MC-3' and MC-4' containing comparative amounts of hydroxyl-functionalized polymers, the use of increased amounts of acid-functionalized polymers P1-1 to P1-5 (multilayers MC-5' to MC-17' of the present invention) in the varnish materials C-I1 to C-I13 of the present invention reduced whitening (Table 5).

[0534] As shown in Table 6, compared to the non-inventive multilayer coating MC-1 prepared from the varnish compositions C-C1 without acid functional polymers, the addition of acid functional polymers P1-1 to P1-5 to the varnish materials C-I1 to C-I13 of the present invention resulted in a significantly improved appearance (due to the reduction in long and short wavelength values ​​and the increase in DOI) without negatively affecting the du, gloss, and haze of the resulting multilayer coatings MC-5 to MC-17 of the present invention. Surprisingly, if acid functional polymers with an acid value of at least 10 mg KOH / g solids were used, only a significantly improved appearance was obtained, while the use of hydroxyl functional polymers with an acid value of less than 10 mg KOH / g solids (compared to multilayer coatings MC-2 to MC-4) resulted in only a slight improvement or no improvement in appearance.

[0535] Compared to the multilayer coating MC-1, the addition of acid-functionalized polymers P1-1, P1-4, or P1-5 also leads to improved flexibility in the multilayer coatings MC-5 to MC-7, MC12 to MC14, or MC15 to MC17 of the present invention. Conversely, compared to the multilayer coating MC-1, a larger amount of hydroxyl-functionalized polymers (MC-3, MC-4) is required to obtain improved flexibility (Table 7).

[0536] In summary, compared to the multilayer coating MC-1 prepared from the comparative varnish material C-C1 which does not contain the acid-functional polymer P1, the addition of the acid-functional polymer P1 to the varnish material (C-I1 to C-I7) containing a mixture of silyl compound R and catalysts C1 and C2 resulted in significant improvements in the appearance and flexibility of the resulting multilayer coatings (MC-5 to MC-11 and MC-5' to MC-11') under wet conditions, as well as steam jet adhesion, without significantly negatively impacting gloss, haze, chipping, solvent resistance, and cross-cut adhesion. Surprisingly, the multilayer coatings MC-2 to MC-4 prepared from the varnish material (C-C2 to C-C4) containing a hydroxyl-functional polymer with an acid value less than 10 mg KOH / g in addition to the mixture of silyl compound R and catalysts C1 and C2 also did not achieve improved appearance and improved flexibility. The beneficial properties of the multilayer coatings of the present invention can be obtained without the use of undesirable crosslinking agents such as polyisocyanates and melamine resins, as well as tin-containing catalysts. Furthermore, the compositions of the present invention can be cured at ambient temperature, thereby making them particularly suitable for touch-up paint applications.

Claims

1. A coating composition comprising: a) At least one silane compound R1 having an isocyanate content of less than 1% and comprising at least one silane group of general formula (I). -NR 1 X-SiR 2 a (OR 3 ) 3-a (I) and optionally at least one silyl group of general formula (II) -N[X-SiR 2 a (OR 3 ) 3-a ] n [X’-SiR 2 b (OR 3 ) 3-b ] m (II) in X and X' are independently straight-chain and / or branched alkylene or cycloalkylene groups having 1-20 carbon atoms; R 1 It is an alkyl group containing 1-10 carbon atoms. R 2 R 3 Each of the alkyl, cycloalkyl, aryl, or aralkyl groups is independently an alkyl, cycloalkyl, aryl, or aralkyl group, and the carbon chain of the alkyl, cycloalkyl, aryl, or aralkyl group may be connected by non-adjacent oxygen, sulfur, or NR. a Group spacers, where R a It is alkyl, cycloalkyl, aryl, or aralkyl. m and n are independent values ​​of 0-2, provided that m+n = 2. a and b are independently 0-2; b) At least one catalyst of general formula (III) C1 z [C(R 4 )(R 5 )(R 6 )-(CH2) n -C(=O)-O - ]M z+ (III) in R 4 -R 6 Each of the residues is independently hydrogen or an alkyl group containing 1-6 carbon atoms, provided that residue R is present. 4 -R 6 The total number of carbon atoms in it is 3-8; z is 1-4; and n is 0 or 1-8 The condition is that, If z = 1, then M is selected from Li, K, and Na; If z = 2, then M is selected from Zn and Zr; If z = 3, then M is selected from Bi and Al; If z = 4, then M is selected from Zr and Ti; c) At least one metal alkoxide C2; d) At least one polymer P1 having an acid value of 60-300 mg KOH / g solid, determined according to procedure A of DIN EN ISO 2114:2002-06; and e) One or more aprotic organic solvents.

2. The coating composition according to claim 1, characterized in that... In general formulas (I) and (II), X and X' independently represent straight-chain alkylene groups having 1-10 carbon atoms; and / or R in general formula (I) 1 It is an alkyl group containing 2-8 carbon atoms; and / or R in general formulas (I) and (II) 3 Each represents C1-C independently. 10 Alkyl groups; and / or In general formulas (I) and (II), a is 0; and / or In equation (II), b is 0.

3. The coating composition according to claim 1, characterized in that... The silane compound R1 is present in a total amount of 5-45% by weight in each case, based on the total weight of the coating composition.

4. The coating composition according to claim 2, characterized in that... The silane compound R1 is present in a total amount of 5-45% by weight in each case, based on the total weight of the coating composition.

5. The coating composition according to claim 4, characterized in that... The silane compound R1 is present in a total amount of 12-35% by weight in each case, based on the total weight of the coating composition.

6. The coating composition according to any one of claims 1-5, characterized in that... The catalyst C1 of at least one of the general formulas (III) is a new decanoate and / or ethylhexanoate of potassium, lithium or titanium.

7. The coating composition according to claim 6, characterized in that... The catalyst C1 of at least one general formula (III) is potassium neodecanoate (I), potassium 2-ethylhexanoate (I), titanium neodecanoate (IV), or titanium 2-ethylhexanoate (IV).

8. The coating composition according to any one of claims 1-5, characterized in that... The at least one catalyst C1 is present in a total amount of 1-50 millimoles of metal per 100 grams of solid silane compound R1.

9. The coating composition according to claim 7, characterized in that... The at least one catalyst C1 is present in a total amount of 1-50 millimoles of metal per 100 grams of solid silane compound R1.

10. The coating composition according to claim 9, characterized in that... The at least one catalyst C1 is present in a total amount of 15-35 millimoles of metal per 100 grams of solid silane compound R1.

11. The coating composition according to any one of claims 1-5, characterized in that... The at least one metal alkoxide C2 is selected from metal alkoxides of general formula (IV). M 1 [(OR 7 ) m (R 8 ) n-m ] n (IV) in R 7 Is it a straight-chain or branched C1-C? 10 alkyl, R 8 It is a halogen group, an acetylacetone group, an alkyl acetoacetate group, or an ethanolamine group. M 1 Represents at least one metal selected from silicon, titanium, tantalum, zirconium, boron, aluminum, magnesium, or zinc. m is an integer between 0 and 4, and n represents M 1 Its valence is 2-5.

12. The coating composition according to claim 9 or 10, characterized in that... The at least one metal alkoxide C2 is selected from metal alkoxides of general formula (IV). M 1 [(OR 7 ) m (R 8 ) n-m ] n (IV) in R 7 Is it a straight-chain or branched C1-C? 10 alkyl, R 8 It is a halogen group, an acetylacetone group, an alkyl acetoacetate group, or an ethanolamine group. M 1 Represents at least one metal selected from silicon, titanium, tantalum, zirconium, boron, aluminum, magnesium, or zinc. m is an integer between 0 and 4, and n represents M 1 Its valence is 2-5.

13. The coating composition according to any one of claims 1-5, characterized in that... The metal alkoxide C2 is titanium isopropoxide (IV) and / or titanium n-butoxide (IV) and / or bis(ethyl acetoacetate) diisopropoxide (IV).

14. The coating composition according to claim 12, characterized in that... The metal alkoxide C2 is titanium isopropoxide (IV) and / or titanium n-butoxide (IV) and / or bis(ethyl acetoacetate) diisopropoxide (IV).

15. The coating composition according to any one of claims 1-5, characterized in that... The at least one metal alkoxide C2 is present in each case as a total amount of 2.5-40 millimoles of metal based on 100 grams of solid silane compound R1.

16. The coating composition according to claim 14, characterized in that... The at least one metal alkoxide C2 is present in each case as a total amount of 2.5-40 millimoles of metal based on 100 grams of solid silane compound R1.

17. The coating composition according to claim 16, characterized in that... The at least one metal alkoxide of general formula (IV) is present in each case with a total amount of 2.5-40 millimoles of metal based on 100 grams of solid silane compound R1.

18. The coating composition according to any one of claims 1-5, characterized in that... The acid value of the at least one polymer P1 is determined according to procedure A of DIN EN ISO 2114:2002-06 to be 60-200 mg KOH / g solid.

19. The coating composition according to claim 16 or 17, characterized in that... The acid value of the at least one polymer P1 is determined according to procedure A of DIN EN ISO 2114:2002-06 to be 60-200 mg KOH / g solid.

20. The coating composition according to claim 19, characterized in that... The acid value of the at least one polymer P1 is determined according to procedure A of DIN EN ISO 2114:2002-06 to be 90-130 mg KOH / g solid.

21. The coating composition according to any one of claims 1-5, characterized in that... It is a varnish composition or a colored varnish composition.

22. The coating composition according to claim 20, characterized in that... It is a varnish composition or a colored varnish composition.

23. The coating composition according to any one of claims 1-5, characterized in that... The coating composition contains at least one crosslinking agent and / or tin-containing compound in an amount of less than 2% by weight based on the total weight of the coating composition.

24. The coating composition according to claim 22, characterized in that... The coating composition contains at least one crosslinking agent and / or tin-containing compound in an amount of less than 2% by weight based on the total weight of the coating composition.

25. The coating composition according to claim 24, characterized in that... The coating composition contains at least one crosslinking agent and / or tin-containing compound in an amount of 0% by weight based on the total weight of the coating composition.

26. A method for forming a coating on a substrate (S), comprising the following steps: (1) Applying the coating composition of any one of claims 1-25 to a substrate (S); (2) A coating film is formed from the coating composition applied in step (1); and (3) Curing the coating film formed in step (2).

27. The coated substrate obtained by the method of claim 26.

28. A multilayer coating comprising at least two coatings, wherein at least one coating is formed from a coating composition according to any one of claims 1-25.

29. A substrate coated with a multilayer coating as defined in claim 28.

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