Coating materials with high solids content and good levelling, multi-coat paint systems produced therefrom and use thereof.

(54) Title: HIGH SOLID CONTENT COATING MATERIALS AND MULTIPLE LAYER PAINTING SYSTEMS WITH GOOD LEVELING PRODUCED FROM THEM AND USES OF THEM.

(54) Title: COATING MATERIALS WITH HIGH SOLIDS CONTENT AND GOOD LEVELING, MULTI-COAT PAINT SYSTEMS PRODUCED THEREFROM AND USE THEREOF.

(57) Summary

The present invention relates to aprotic solvent based coating materials, comprising at least one oligomeric and / or polymeric hydroxyl-containing compound (A) and at least one compound (8) having isocyanate groups and having at least one silane group of formula (I): -X-Si-RG3-X (I) where G = identical or different hydrolyzable groups, more particularly G alkoxy group (OR '), R' hydrogen, alkyl or cycloalkyl, being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, where Ra = alkyl, cycloalkyl, aryl or aralkyl, X = organic radical, more particularly alkylene or linear and branched cycloalkylene radical having 1 to 20 carbon atoms, R = alkyl, cycloalkyl, aryl or aralkyl, it being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, where Ra = alkyl, cycloalkyl, aryl or aralkyl, x = oa 2, further characterized in that (i) compound (B) containing groups Isocyanate and silane groups contain uretdione groups, and (ii) compound (B) has been prepared from a linear aliphatic diisocyanate. The present invention further provides multi-layer coating methods using these coating materials, and also the use of the coating materials as a clearcoat material, and application of the coating method for automotive restoration and / or for the coating of plastic substrates. .

(57) Abstract

The present invention relates to coating materials based on aprotic solvents, comprising at least one oligomeric and / or polymeric hydroxyl-containing compound (A) and at least one compound (B) having isocyanate groups and having at least one silane group of the formula ( I): -X-Si-RxG3-x where G = identical or different hydrolysable groups, more particularly G = alkoxy group (OR '), R' = hydrogen, alkyl or cycloalkyl, it being possible for the carbon Chain to be interrupted by nonadjacent oxygen , sulfur or NRa groups, where Ra = alkyl, cycloalkyl, aryl or aralkyl, X = organic radical, more particularly linear and / or branched alkylene or cycloalkylene radical having 1 to 20 carbon atoms, R = alkyl, cycloalkyl, aryl or aralkyl, it being possible for the carbon Chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, where Ra = alkyl, cycloalkyl, aryl or aralkyl, x = 0 to 2, characterized in that (i) the compound (B) containing isocyanate groups and silane groups has uretdione groups, and (ii) the compound (B) has been prepared from a linear aliphatic diisocyanate. The present invention further provides multi-stage coating methods using these coating materials, and also the use of the coating materials as clearcoat material, and application of the coating method for automotive refinishing and / or for the coating of plastics substrates.

COATING MATERIALS WITH HIGH CONTENT OF

SOLIDS AND MULTIPLE LAYER PAINT SYSTEMS WITH

GOOD LEVELING PRODUCED FROM THEM AND USE OF THE

SAME

The present invention relates to coating compositions based on aprotic solvents and comprising at least one oligomeric and / or polymeric hydroxyl-containing compound (A) and also at least one compound (B) having isocyanate groups and having silane groups.

Coating compositions of this kind are known from WO 08/74491, WO 08/74490 and WO 08/74489, for example. Compound (B) used in these coating compositions and containing isocyanate groups and silane groups is based on known isocyanates, preferably biuret dimers and isocyanurate trimers of diisocyanates, more particularly of hexamethiolene diisocyanate. These coating compositions of WO 08/074489 have the advantage over conventional polyurethane coating compositions of significantly improved starch resistance one after the other with good weathering stability. The coating compositions described herein are more particularly used in automotive OEM finishing, although their use in automotive restoration is also described. A disadvantageous aspect to these coating compositions, however, is that a reduction in the solvent fraction, in other words an increase in the non-volatile fraction, of the coating compositions is associated with a deterioration in flow properties and by both with a significant impairment of the optical quality of the resulting coatings.

The coating compositions used for the automotive restoration segment, however, are affected by regulatory emission guidelines (eg German Federal Air Pollutants Standard 31 “German Federal Airborne Poilutants

Ordinance 31 ”). The current European directive recommends a 420 g / l VOC (“volatile organic content”) for clearcoat systems, resulting, depending on the density of the system used, of non-volatile fractions of around 60% by weight. A problematic aspect in the development of systems having a high non-volatile fraction is that in general there is an increase in viscosity and therefore a reduction in the fluidity of the system, with adverse consequences for the resistance to flow and the final coat of paint. To counteract this effect, it is necessary to raise the non-volatile fraction while maintaining the same viscosity. This is generally accomplished by reducing the viscosity of the curing agent and / or the binder. However, doing so often encompasses a deterioration in physical film formation, and results in longer drying times. Especially for coating compositions that are used in the automotive restoration segment, this condition is disadvantageous, since the coating compositions used in the restoration segment offer long reaction times in any case.

US-A-5,691,439 describes coating compositions which, in addition to hydroxyl-containing binders (A), comprise compounds (B) with isocyanate groups as linkers, it being essential to the invention that compounds (B) also have silane groups or groups siloxane, in order to reduce the energy of the surface, and also have allophanate groups, in order to obtain transparent coatings, which means that the coatings are obtained which have improved surface properties. However, that specification lacks detail as to how the solvent fraction of the coating compositions can be reduced while still ensuring high cure rates even under automotive restoration conditions.

In addition, EP-A 1 273 640 describes 2K [2-component] coating compositions, comprising a polyol component and an interlocking component consisting of aliphatic polyisocyanates and / or oc I c or I if a teos or derived polyisocyanates. of them by polymerization, allophanatization, biuretization or urethaneization, with 0.1 to 95 mole% of the originally free isocyanate groups present having gone through reaction with bisaIcoxis¡IiIamina. These coating compositions can be used to produce clearcoats or finish coatings in the automotive segment and, when fully cured, exhibit high scratch resistance along with high resistance to environmental influences. However, that specification lacks detail as to how the solvent fraction of the coating compositions can be decreased while still ensuring high cure rates, even under automotive finishing conditions, and without detracting from the surface properties of the resulting coatings.

WO 2001/98393 describes 2K [2-component] coating compositions comprising a polyol as a binder component and, as an interleaver component, a polyisocyanate functionalized in low fractions with alkoxysilylamines, preferably with bisalkoxysilylamines. These coating compositions are used in particular as basecoats (primers) and are optimized for adhesion to metal substrates, preferably to aluminum substrates.

So far, the unpublished international patent publication PCT / US 2010/028308 describes coating compositions which in addition to a hydroxyl-containing component (A) and an isocyanate group-containing component (B) comprise the reaction product of a uretdione with a bisalkoxysilylamine or with a monoalkoxysilylamine, but the reaction production of uretdione with alkoxysilylamine no longer contains any residual isocyanate groups.

EP-B-864 575 describes compounds having alkoxysilane groups and urea groups and obtained by reacting polyisocyanates, such as uretdiones and / or isocyanurates, for example, with secondary monoalkoxysilylamines containing ester groups, such as, more particularly, N- (3-1rimethoxysiIiIpropiI) diethyl aspartate. Compounds having alkoxysilane groups and urea groups no longer contain substantially any remaining isocyanate groups, and in accordance with EP-B-864 575 are used, optionally together with more silane group-containing components, in coating compositions that cure exclusively by silane polycondensation. The use of these compounds having alkoxysilane groups and urea groups together with hydroxy containing components and isocyanate group containing components, on the other hand, is not described in EP-B-864 575.

Finally, EP-A-1 426 393 describes polyisocyanates that contain uretdione groups, are low in monomer content, and have the advantage that their stability with respect to retrograde cutting is improved over that of the previously used uretdiones. This improved stability with respect to retrograde cutting is acquired by dimerizing the uretdiones at temperatures of <= 40 ° C in the presence of trialkylphosphines and then separating the trialkylphosphines. Uretdiones are used, for example, as curing agents in coating compositions. That specification, however, lacks details of how the surface properties of the resulting coatings can be influenced, and details of how effective cure can be ensured even under restorative conditions.

issue

The problem addressed by the present invention, therefore, was that of providing coating compositions, more particularly for automotive restoration, which ensure effective cure even under restoration conditions, have a high solids content and therefore a very low content of solvent, exhibit good flow resistance and final coat of paint, and lead to coatings having good surface properties.

The overall optical appearance was evaluated by measuring the surface profile of the applied and baked coating films, using the wavescan method, which allows measurement of the visible profile of coating film surfaces. For this purpose, the intensity of reflection ("ripple") was measured by means of the Byk-Gardner Wave Sean instrument, registering 1250 measurement points over a distance of 10 cm. The instrument divides the reflection into long undulation (“long wave”), that is, the discrepancy in light intensity for structures in the range of 0.6 mm to 10 mm, and into short undulation (“short wave”), that is, the discrepancy in light intensity for structures in the range of 0.1 mm to 0.6 mm. For a good appearance, low long length measurement values ​​in the resulting coatings, for very low film thicknesses, are particularly critical.

Furthermore, the intention was to provide coating compositions that lead to a highly stable network to weathering and at the same time ensure high acid resistance. Furthermore, the intention was that the coating compositions should lead to coatings that are highly scratch resistant and more particularly exhibit a high level of gloss retention after scratch exposure. Additionally, paint coatings and finishes, especially clearcoats, must be capable of being produced even in film thicknesses> 40 pm without stress cracking occurring. In addition, the coating compositions must meet the requirements typically imposed on the clearcoat film in automotive OEM finishes and automotive restorations.

Finally, the new coating compositions should be easily producible and with very good reproducibility, and should not cause any environmental problems in the course of paint application.

Solution to the problem

In view of the statement of the problem identified above, it has been discovered that coating compositions that are based on aprotic solvents, comprising at least one compound (A) containing oligomeric and / or polymeric hydroxyl and at least one compound (B ) having isocyanate groups and having at least one silane group of the formula (I)

-XS¡-R ”_xG₃-x (I) with

G = identical or different hydrolyzable groups, in particular G = alkoxy group (OR '),

R '= hydrogen, alkyl or cycloalkyl, being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra = alkyl, cycloalkyl, aryl or aralkyl, preferably R' = ethyl and / or methyl,

X = organic radical, more particularly non-linear and / or branched alkylene or o-cloace radical having 1 to 20 carbon atoms, most preferably X = alkylene radical having 1 to 4 carbon atoms,

R "= alkyl, cycloalkyl, aryl or aralkyl, being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra = alkyl, cycloalkyl, aryl or aralkyl, preferably R" = alkyl radical, more particularly having 1 to 6 carbon atoms, x = 0 to 2, preferably 0 to 1, more preferable x = 0 further characterized in that (i) compound (B) containing isocyanate groups and silane groups contains uretdione groups, and (ii) compound (B) has been prepared from a linear aliphatic diisocyanate (DI).

The present invention further provides multi-stage coating methods using these coating compositions, and the use of the coating compositions as a clearcoat, and application of the coating method for coating components for installation in or on automobiles and / or plastic substrates and for automotive restoration.

In view of the prior art, it was surprising and unpredictable to one skilled in the art that the problems addressed by the present invention could be solved with the help of the coating compositions of the invention.

Therefore, it was particularly surprising that the coating compositions of the invention exhibit effective cure even under restorative conditions, have a high solids content and therefore a very low solvent content, exhibit good flow resistance and a final coat of paint. , and lead to coatings having good surface properties. Consequently, the resulting coatings have low long-wavelength measurement values ​​at very low film thicknesses that are particularly important for good appearance.

Furthermore, the coating compositions result in a highly stable network to weathering and at the same time ensure high acid resistance. Furthermore, the coating compositions give coatings that are highly scratch resistant and more particularly exhibit a high level of gloss retention after scratch exposure. Additionally, paint coatings and finishes, especially clearcoats, can be produced even at film thicknesses> 40 pm without stress cracking. On these grades, the coating compositions meet the requirements typically imposed on clearcoat film in automotive OEM finishes and automotive restorations.

Finally, the new coating compositions can be produced easily and in a very reproducible way, and they do not give rise to any environmental problem during the application of paint.

DESCRIPTION OF THE INVENTION

The coating compositions of the invention

The coating compositions of the invention, more particularly, are thermally curable coating compositions, i.e. preferably coating compositions that are substantially free of radiation-curable unsaturated compounds, more particularly being completely free of unsaturated compounds radiation curable.

Compounds containing isocyanate group (B)

As component (B), the coating compositions of the invention comprise one or more compounds having free isocyanate groups, that is, unblocked and / or blocked. The coating compositions of the invention preferably comprise compounds (B) having free isocyanate groups. The free isocyanate groups of the isocyanate group-containing compounds B can also be used, however, in blocked form. This is preferably the case when the coating compositions of the invention are employed in the form of one-component systems.

It is essential to the invention that the isocyanate group-containing compound used as component (B) in the coating compositions has been prepared from at least one linear aliphatic diisocyanate (DI). This ensures that the resulting compounds (B) can be used in the form of high solids solutions having a solids content of more than 7 0% by weight, more particularly at least 75% by weight, in the coating compositions of the invention, while at the same time producing coatings whose surface properties, such as flow in particular, are very good.

The isocyanate group-containing compound used as component (B) in the coating composition has preferably been prepared from at least one linear aliphatic diisocyanate (DI) having 3 to 12 carbon atoms, more particularly having 4 to 10 carbon atoms , and especially having 5 to 6 carbon atoms.

Examples of suitable linear aliphatic diisocyanates (DI) for preparing component (B) are butane diisocyanate, pentane diisocyanate, hexane diisocyanate, octane diisocyanate, nonane diisocyanate, dean diisocyanate, diisocyanate undecanoate dodecane diisocyanate, and more particularly hexane diisocyanate.

Furthermore, it is essential to the invention that the isocyanate group-containing compound (B) contain uretdione groups as well as free and / or blocked isocyanate groups. As a result of this use of isocyanate group containing compounds having uretdione groups, in contrast to the use of isocyanurates and in contrast to the use of biurets and / or allophanates of the same diisocyanates, coatings having substantially better surface properties are obtained , more particularly having smaller long wave values. The long wave values ​​of the applied and baked coating films are measured by means of the wavescan method, which allows measurement of the visible profile of coating film surfaces. For this purpose, the intensity of reflection (undulation ”) was measured by means of the Byk-Gardner Wave Sean instrument, recording 1,250 measurement points over a distance of 10 cm. The instrument divides the reflection into long-wave undulation (“long wave”), that is, the discrepancy in light intensity for structures in the range of 0.6 mm to 10 mm, and into short-wave undulation (“short wave”), that is, the discrepancy in Light Intensity for structures in the range of

0.1mm to 0.6mm.

Preferably, therefore, compound (B) has been prepared from a polycyanate (Pl) having a uretdione group> 50 mol%, preferably more than 50 to 90 mol%, more preferably 65 to 80 mol%, based on each case in the totality of the structural types formed by oligomerization of isocyanate of linear aliphatic diisocyanate (DI). Suitable uretdiones to prepare component (B) are also described, for example, in EP-A-1 426 393, page 2, paragraph [0012], to page 4, paragraph [0030],

It is known that commercial uretdiones can contain 5% to 30% by weight of the corresponding isocyanurate of the respective diisocyanate, based in each case on the total weight of the commercial product. This Isocyanurate fraction is not necessarily preferred, but generally also causes no problem in the context of subsequent reaction with the silane group containing compounds mentioned below (Ha) and (Illa). However, in that case, on the reaction of the commercial uretdione with the uretdione group-containing compounds mentioned below (lia) and (Illa) as well as the uretdione group-containing compounds (B) of the invention, the functionalized isocyanurates correspondingly they are also obtained. These functionalized isocyanurates should then be formally considered as belonging not to the uretdione β group-containing component, but to the (BS) component described in detail below.

The isocyanate group-containing compound used as component (B) in the coating composition comprises, in addition to free and / or blocked isocyanate groups and in addition to uretdione groups, at least one silane group of formula (I)

-XS¡-R ”_xG₃._x (I) with

G = identical or different hydrolyzable groups, in particular G = alkoxy group (OR '),

R '= hydrogen, alkyl or cycloalkyl, being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra = alkyl, cycloalkyl, aryl or aralkyl, preferably R' = ethyl and / or methyl,

X = organic radical, more particularly linear and / or branched alkylene or cycloalkylene radical having 1 to 20 carbon atoms, most preferably X - alkylene radical having 1 to 4 carbon atoms,

R "-alkyl, cycloalkyl, aryl or aralkyl, being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra-alkyl, cycloalkyl, aryl or aralkyl, preferably R" = alkyl radical, more particularly having 1 to 6 carbon atoms, χ = O to 2, preferably O to 1, more preferable x = 0.

Preferably, the coating composition comprises at least one isocyanate group-containing compound (B) which in addition to free and / or blocked isocyanate groups and in addition to uretdione groups further comprises at least one structural unit (II) of the formula (II)

-NR (XS¡R ”_x(OR ')₃-x) (II) and at least one structural unit (III) of formula (III)

-N (XS¡R ”_x(ORj₃._x)_n(X'-S¡R ”and (OR ')₃._and)_m (III) where

R = hydrogen, alkyl, cycloalkyl, aryl or aralkyl, it being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra = alkyl, cycloalkyl, aryl or aralkyl,

R '= hydrogen, alkyl or cycloalkyl, it being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra-alkyl, cycloalkyl, aryl or aralkyl, preferably R'-ethyl and / or methyl,

X, X '= linear and / or branched alkylene or cycloalkylene radical having 1 to 20 carbon atoms, preferably X, X' = alkylene radical having 1 to 4 carbon atoms,

R "= alkyl, cycloalkyl, aryl or aralkyl, being possible for the carbon chain to be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra = alkyl, cycloalkyl, aryl or aralkyl, preferably R" = alkyl radical, more particularly having 1 to 6 carbon atoms, n = 0 to 2, m = 0 to 2, m + n = 2, yx, y = 0 to 2.

The respective preferred alkoxy radicals (OR ') may be similar or different, which is critical to the construction of the radicals, however, is the one which may influence the reactivity of hydrolyzable silane groups. Preferably R 'is an alkyl radical, more particularly having 1 to 6 carbon atoms. Particularly preferred radicals R 'are those that increase the reactivity of silane groups, that is, they represent good leaving groups. In this sense, a methoxy radical is preferred over an ethoxy radical, which in turn is preferred over a propoxy radical. With particular preference, therefore, R '= ethyl and / or methyl, more particularly methyl.

The reactivity of organofunctional silanes can also be considerably influenced, in addition, by the length of the spacers X, X 'between silane functionality and organic functional group serving for reaction with the modifying constituent.

By way of example of this, mention can be made of the "alpha" silanes, which are available from the Wacker company, and where there is a methylene group, instead of the propylene group present in the case of "gamma" silanes, among Si atom and functional group.

The isocyanate group containing compounds (B) used according to the invention and functionalized with the structural units (II) and (III) are most preferably obtained by reaction of the uretdione group containing polyisocyanates (Pl) - prepared by oligomerizing the diisocyanates linear aliphatic (DI) - with at least one compound of the formula (Ha)

H-NR- (X-SiR ”_x(OR ')₃__x) (lia), and with at least one compound of the formula (Illa)

HN (X-SiR ”_x(OR ')₃._x)_n(X'-SiR ”_and(OR ')₃._and)_m (Illa), the substitutes being as defined above.

Inventively preferred compounds (Illa) are b, (2-ethyltrimethoxysilyl) amine, bi (3-propyltrimethoxysilyl) amine, bi (4-butyltrimethoxysilyl) amine, bi (2-ethyltriethoxysilyl) amine, bi (3-propyltriethoxysilyl) -amine and / or bi (4-buti11rietoxisiIiI) amine. Especially preferred is bi (3-propi11rirn etoxisi I i I) amin a. Aminosilanes in this class are available, for example, under the tradename Dynasylan® from Degussa or Silquest® from OSI.

Inventively preferred compounds (Ha) are aminoa I qui 11 ria I coxisi I anos, such as, preferably, 2-aminoethyltri5 methoxysilane, 2-aminoethyltriethoxysilane, 3-aminopropyltrimethoxysilane,

3-aminopropyltriethoxysilane, 4-aminobutyltrimethoxysilane, 4-aminobutyltriethoxysilane. Particularly preferred compounds (la) are N (2- (trimethoxysilyl) ethyl) alkylamines, N- (3- (trimethoxysilyl) propyl) alkylamines, N- (4- (trimethoxysilyl) butyl) alkylamines, N- (2- (triethoxysilyl) ) ethyl) 10 alkylamines, N- (3- (triethoxysiIi) propiI) aIquiIamines and / or N- (4- (triethoxysilyl) butyl) alkylamines. N- (3- (trimethoxysilyl) propi!) Butylamine is especially preferred. Aminosilanes in this class are available, for example, under the trade name Dynasylan® from Degussa or

Silquest® by OSI.

It is preferred that the isocyanate group-containing compound (B) be between 2.5 and 90 mol%, more particularly 5 to 85 mol%, and most particularly 7.5 to 80 mol%, of at least one structural unit (II) of formula (II), and 10.0 to 97.5 mol%, more particularly 15 to 95 mol%, and very particularly 20 to 92.5 mol%, of at least one structural unit (III) of formula (III), with base in each case on all the structural units (II) and (III).

In particular, it is preferred that the total fraction of the isocyanate groups in the polylysoclanate (Pl) is reacted to form the structural units (II) and / or (III) between 5 a and 95 mol%, preferably between 10 and 85 mol%, and more preferable between 15 and

0% molar.

Especially preferred isocyanate group-containing compounds (B) are reaction products of hexamethylene 1,6-diisocyanate uretdione with bi (3-propi 11 rimethoxysi I i) amine and N- (3- (trimethoxysiIiI) propiI) butylamine.

The solids content of the polyisocyanate curing agent (B) used according to the invention is advantageously more than 70% by weight, preferably at least 75% by weight.

In addition to the essentially inventive component (B), the coating composition may further comprise one or more compounds (BS) that are different from component (B) and that have free and / or blocked isocyanate groups. The coating compositions of the invention preferably comprise compounds (BS) having free isocyanate groups. The free isocyanate groups of the isocyanate group containing components (BS), however, can also be used in blocked form. This then is preferably the case when the coating compositions of the invention are used as one-component systems.

As component (BS) it is possible to use substituted or unsubstituted, aromatic, aliphatic, cycloaliphatic and / or heterocyclic diisocyanates and / or polyisocyanates which are known per se. Examples of preferred polyisocyanates are as follows:

2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane disocyanate, p-phenylene diisocyanate, biphenyl diisocyanates, 3,3-diisocyanate '-dimet ¡I - 4,4' - d if eni I e η o, tetramethylene 1,4-diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexane 1,6-diisocyanate, isophorone diisocyanate, diisocyanate ethylene, 1,1 2-dodecane diisocyanate, 1,3-cyclobutane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate,

<td>methylcyclohexyl,</td><td>2,4-diisocyanate</td><td>of</td>

<td>-isocyanate of</td><td>hexahydrotoluene,</td><td> 1.3-</td>

<td>hexahydrophenylene,</td><td>1,4-diisocyanate</td><td>of</td>

hexahydrophenylene diisocyanate, 2,4'-disocyanate perhydrodiphenylmethane, 4,4'-methylene dicyclohexyl diisocyanate (for example, Desmodur®

W from Bayer AG), tetra m eti Ixi Ilo diisocyanates (eg TMXDI® from American Cyanamid), and mixtures of the above-mentioned naturally occurring polyisoda. Further preferred polyisocyanates are biuret dimers and isocyanurate trimers of the aforementioned diisocyanates.

Particularly preferred compounds (BS) are hexamethylene 1,6-diisocyanate, isophorone diisocyanate and 4,4'-methylenediocyclohexyl diisocyanate, their biuret dimers and / or isocyanurate trimers.

In another embodiment of the invention, the compounds (BS) are polyisocyanate prepolymers with urethane structural units, and are obtained by reacting polyols with a metric excess of the aforementioned polyisocyanates. Such polyisocyanate prepolymers are described in US-A-4,598,1 31, for example.

As component (BS) it is also possible to use compounds containing isocyanate group (BS) that are functionalized with structural units (I), (II) and / or (III). The compounds. (BS) then differ from component (B) generally in that they have no or at most small amounts of uretdione groups.

The isocyanate group-containing compounds (BS) functionalized with the structural units (II) and (III) are particularly preferably prepared by reacting the above-mentioned diisocyanates and / or polyisocyanates with the above-mentioned compounds (lia) and (Illa), by reacting between 2.5 and 90 mol%, preferably 5 to 85 mol%, more preferably 7.5 to 80 mol%, of the isocyanate groups in the origin polyisocyanate structure with at least one compound (Ha)

H-NR- (X-YES_x(OR ')₃-x) (Ha), and

between 2.5 and 90 mol%, preferably 5 to 85 mol%, more preferably 7.5 to 80 mol% of the isocyanate groups in the origin polyisocyanate structure with at least one compound (Illa)

HN (XS¡R ”_x(OR ')₃.x) n (X'-S¡R ”_and(OR ')₃-_and) m (Illa), the substitutes being as defined above. The total proportion of isocyanate groups reacted with compounds (lia) and (Illa) in polyisocyanate compound (BS) is between 5 and 95 mol%, preferably between 10 and 90 mol%, more preferably between 15 and 85 mol% of the isocyanate groups in the origin polyisocyanate structure.

Particularly preferred isocyanate group (BS) containing compounds functionalized with silane groups are reaction products of 1,6-hexamethylene diisocyanate and / or isophorone diisocyanate, and / or its isocyanurate trimers, with bis (3-propyltrimethoxysilyl) amine and / or N- (3- (trimethoxysilyl) propyl) butylamine.

In addition to this or this compound or compounds (BS) added separately to the coating compositions of the invention, the component (BS) also includes the isocyanate group containing compounds fractions functionalized with silane groups, which compounds are introduced into the coating composition by means of the isocyanurate and / or higher homolog fraction that is frequently present in commercial uretdiones.

Wherein, in addition to component (B), the coating composition also comprises one or more compounds (BS) that are different from component (B) and that have free and / or blocked isocyanate groups, the total fraction of the reacted isocyanate groups to form the silane structural units (I), (II) and (III) it is between 5 and 95 mol%, preferably between 10 and 90 mol%, more preferably between 15 and 85 mol%, based in each case on all isocyanate groups originally present in component (B) plus component (BS).

Wherein, in addition to component (B), the coating composition also comprises one or more compounds (BS) that are different from component (B) and that have free and / or blocked isocyanate groups, the mixing ratio of the component containing uretdione group (B) to component (BS) is preferably between 1.0 equivalent of component (B) to 40.0 equivalent of component (BS) and 1.0 equivalent of component (B) to 0.01 equivalent of component (BS), more preferable between 1.0 equivalent of component (B) to 0.02 equivalent of component (BS), and very particularly preferably between 1.0 equivalent of component (B) to 25.0 equivalent of component (BS) and 1.0 equivalent of component (B) to 0.05 Component Equivalents (BS).

The equivalents of component (B) and (BS), respectively, are determined in this case in the usual way, by dividing the amount used, in grams, by the equivalent weight of compound (B) or (BS). The fraction of isocyanurate group-containing compounds that may be present in the commercial compounds (B) containing uretdione groups is given to component (B), for simplicity, when calculating the mixing ratio in equivalents; in other words, in the calculation set forth below, an Idealized compound (B) is assumed, in particular since the fraction of compound containing Isocyanurate group in (B), which is low at most, and perhaps not present, would have only an extremely small influence on the equivalent relationship.

To determine the equivalent weight of compound (B), an arithmetic determination is first made of the equivalent weight EEW of the free silane group compound (B) in grams, in a known manner, from the content of isocyanate group measured in accordance with DIN EN ISO 3219 / A.3, in% by weight, as follows:

EEW (B silane-free) = (100% by weight * 42 g) / isocyanate content in% by weight

The equivalent weight EEW of the sllanized compound (B) in grams is also determined arithmetically by means of the previously described equivalent weight EEW of the non-silanized compound (B), the fraction of the silanized isocyanate groups c, the fraction of silane units (I) thus, the fraction of silane units (II) as2, the fraction of silane units (III) as3, and also the theoretical equivalent weights of the silane units, (I), (II) and (III) , as follows:

EEW (B silanized) = EEW (Silane-free B) + c * [(as1 * EEW (I)) + (as2 * EEW (II)) + (as3 * EEW (III))] where c = degree of conversion of the isocyanate groups originally present in B to silane units of the formulas (I) + (II) + (III) in mol%, divided by .100 mol% thus = fraction of the isocyanate groups reacted in B to give structural units (I), in mole%, divided by 100 mole%, with the proviso that the sum of the structural units (I) + (II) + (III) is always 100 mol% as2 = fraction of the isocyanate groups reacted in B to give the structural units (II), in mol%, divided by 100 mol%, with the proviso that the sum of the structural units (I) + (II) + (III) is always 100 mol% as3 = fraction of the isocyanate groups reacted in B to give the structural units (III ), in mole%, divided by 100 mole%, with the proviso that the sum of the structural units (I) + (II) + (III) is always 100% molar

EEW (I) = equivalent weight, arithmetically determined from the structural formula, for the structural unit (I): -X26

S¡-R "xG3-x, where X, R", G and x are as defined above for formula (I)

EEW (II) = equivalent weight, arithmetically determined from the structural formula, for the structural unit (II): NR- (X-SiR "x (OR ') 3-x), where X, R", R' and x are as defined above for formula (II)

EEW (lll) = equivalent weight, arithmetically determined from the structural formula, for the structural unit (III): N (X-SiR ”x (OR ') 3-x) n (X'-S¡R” y (ORj3 -y) m, where X, R ", R 'and x are as defined above for formula (III).

In order to determine the equivalent weight of the compound (BS), an arithmetic determination is first made, in turn, of the equivalent weight EEW of the free silane group compound (BS), in grams, in a manner known from the content of Isocyanate group measured according to DIN EN ISO 3219 / A.3, in% by weight, as follows:

EEW (BS silane-free) = (100% by weight * 42 g) / isocyanate content in% by weight

The equivalent weight EEW of the silanized compound (BS) in grams is also determined arithmetically by means of the previously described equivalent weight EEW of the non-silanized compound (BS), the fraction of the silanized isocyanate groups c ', the fraction of units of silane (I) as'1, the fraction of silane (II) units as'2, the fraction of silane (III) units as'3, and also the theoretical equivalent weights of the silane units, (I), (II) and (III), as follows:

EEW (silanized BS) = EEW (silane-free BS) + c '* [(as'1 * EEW (I)) + (as'2 * EEW (II)). + (As'3 * EEW (III) )] where c '= degree of conversion of the isocyanate groups originally present in (BS) to silane units of formulas (I) + (II) + (III) in molar%, divided by

100% molar as'1 = fraction of reacted isocyanate groups and^:n BS to give the structural units (I), in mol%, divided by 100 mol%, with the proviso that the sum of the structural units (I) + (II) + (III) is always

0 0 mol% as'2 = fraction of the isocyanate groups reacted in BS to give the structural units (II), in mol%, divided by 100 mol%, with the condition that the sum of the structural units (I) + (II) + (III) always be

0 0 mol% as'3 = fraction of the isocyanate groups reacted in BS to give the structural units (III), in mol%, divided by 100 mol%, with the condition that the sum of the structural units (I) + ( II) + (III) always be

one 00% molar.

The hydroxyl-containing compound (A)

As the hydroxyl-containing compound (A), use is made of at least one oligomeric and / or polymeric polyol.

Preferred oligomeric and / or polymeric polyols (A) have average mass molecular weights Mw> 500 daltons, as measured by gel permeation chromatography (GPC) against a polystyrene standard, preferably between 800 and 100,000 15 daltons , more particularly between 1000 and 50,000 daltons. · '

- Particular preference is given to polyester polyols, polyurethane polyols, polysiloxane polyols. polyacrylate polyols and / or polymethacrylate polyols, and also their copolymers, referred to below as polyacrylate polyols.

Polyols preferably have an OH number of 30 to

400 mg KOH / g, more particularly between 100 and 300 KOH / g. The hydroxyl number (OH number) indicates how many mg of potassium hydroxide are equivalent to the amount of acetic acid bound by 1 g of substance in acetylation. It is determined by boiling the sample with acetic anhydride-pyridine and titrating the resulting acid against potassium hydroxide solution (DIN 53240-2).

The glass transition temperatures as measured by DSC according to DIN-EN-ISO 1 1 357-2 for polyols 5 are preferably between -150 and 100 ° C, more preferably between 120 ° C and 80 ° C.

Suitable polyester polyols are described in EP-A-0 994 117 and EP-A-1 273 640, for example. Polyurethane polyols are preferably prepared by reaction of polyester polyol prepolymers with suitable diisocyanates or polyisocyanates, and are described in EP-A-1,273,640, for example. Suitable polysiloxane polyols are described in WO-A-01/09260, for example, being^: It is possible for the polysiloxane polyols recited there to be preferably used in combination with other polyols, more particularly those having higher glass transition temperatures.

Poly (meth) acrylate polyols which are especially preferred in accordance with the invention are generally copolymers and preferably have average mass molecular weights Mw of between 1000 and 20,000 daltons, more particularly between

one 50.0 and 10,000 daltons, in each case as measured by gel permeation chromatography (GPC) against a polystyrene standard.

The glass transition temperature of the copolymers is generally between -100 and 100 ° C, more particularly between -50 and 80 ° C (as measured by DSC in accordance with DIN-EN-ISO 1 1357-2).

The poly (meth) acrylate polyols preferably have an OH number of 60 to 250 mg KOH / g, more particularly between 70 and 200 KOH / g, and an acid number of between 0 and 30 mg KOH / g.

The hydroxyl number (OH number) indicates how many mg of potassium hydroxide are equivalent to the amount of acetic acid bound by 1 g of substance in acetylclone. It is determined by boiling the sample with acetic anhydride-pyridine and titrating the resulting acid • against potassium hydroxide solution (DIN 53240-2). The acid number here Indicates the number of mg of potassium hydroxide consumed in neutralizing 1 g of the respective compound (DIN EN

ISO 2114).

As hydroxyl-containing monomeric units, it is preferred to use hydroxyalkyl acrylates and / or hydroxyalkyl methacrylates, such as, more particularly, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxy acrylate, or , 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, and, more particularly, 4-hydroxybutyl acrylate and / or 4-hydroxybutyl methacrylate.

As further monomer units for poly (meth) acrylate polyols, it is preferred to use alkyl methacrylates and / or alkyl methacrylates, such as, preferably, ethyl acrylate, ethyl methacrylate, propyl acrylate, acrylate isopropyl, isopropyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, amyl acrylate, amyl methacrylate, Hexyl Acrylate, Hexyl Methacrylate, Ethylhexyl Acrylate, Ethylhexyl Methacrylate, 3,3,5tri-meti-I-hexyl-acrylate, 3,3,5-tr-met-I-hex-I-methacrylate, or Stearyl Acrylate , stearyl methacrylate, lauryl acrylate or laurllo methacrylate, cycloalkyl acrylates and / or cycloalkyl methacrylates, such as cyclopentyl acrylate, cyclopentyl methacrylate, isobornyl acrylate, isobornyl methacrylate, or, in particular, cyclohexyl acrylate and / or cyclohexyl methacrylate.

As further monomeric units for poly (meth) acrylate chickles, it is possible to use vinyl aromatic hydrocarbons such as vlnttoluene, Ifa-methylstyrene, or, in particular, styrene, amides or nitriles of acrylic acid or methacrylic acid, esters vi η II Icos or ethers vlnl Ileos, and also, in minor amounts, in particular acrylic acid and / or methacrylic acid.

To further increase the solids content of the coating compositions of the invention and further improve surface quality (lower long wave values), particularly in the case of a relatively low degree of silanization of compound (B) , use is made in particular of compounds modified with lactone, containing hydroxyl, oligomers and / or polymers (A). Particular preference is given to using compounds modified with εcaprolactone, containing hydroxyl, oligomeric and / or polymeric (A), and very particular preference to using polyacrylate polyols modified with ε-caprolactone, containing hydroxyl and / or polyols of ρο I and meta cr Ilate modified with ε-caprolactone, containing hydroxyl.

Lactone modified, especially ε-caprolactone modified, hydroxyl-containing, oligomeric and / or polymeric compounds can be prepared in a manner known to one skilled in the art by first preparing the oligomeric and / or polymeric hydroxyl-containing compounds and then react them with lactone or with ε-caprolactone. An alternative option is first subjected to a portion of the monomeric synthesis components, more particularly a portion of the hydroxyl-containing monomeric synthesis components, to reaction with lactone, or with ε-caprolactone, and then to construct the oligomer or polymer Lactone-modified or ε-caprolactone modified. Hydroxyl containing compounds (A) modified with lactone, or with ε-caprolactone, are also described, for example, in US-A4,546,046, column 4, line 24 to column 7, line 6.

In another embodiment of the invention, the hydroxyl-containing compound A can also contain silane groups (I) as well as hydroxyl groups.

The combination of components (A) and (B), and more components of the coating composition

The weight fractions of polyol (A) and polyisocyanate (B) are preferably selected such that the molar equivalent ratio of the unreacted isocyanate groups of the isocyanate-containing compounds (B) to the hydroxyl groups of the compounds which contain hydroxyl (A) is between 0.8: 1 and 1: 1.2, preferably between 0.9: 1 and 1.1: 1, more preferable between 0.95: 1 and

1.05:1.

It is preferred in accordance with the invention to use coating compositions comprising from 20% to 80% by weight, preferably from 30% to 70% by weight, based in each case on the solids content of the coating composition, of at least one hydroxyl-containing polyacrylate (A) and / or at least one hydroxyl-containing polymethacrylate (A).

It is preferred in accordance with the invention to use coating compositions comprising from 20% to 80% by weight, preferably from 30% to 70% by weight, based in each case on the solids content of the coating composition, of at least one isocyanate group-containing compound (B).

Wherein the coating composition, in addition to component (B), also comprises one or more compounds (BS) that are different from component (B) and that have free and / or blocked isocyanate groups, the weight fractions of the polyol (A ), The polyisocyanate (B) and the polyisocyanate (BS) are preferably selected such that the molar equivalent ratio of the unreacted isocyanate groups of the isocyanate containing compounds (B) plus (BS) to the hydroxyl groups of the compound containing hydroxyl (A) is between 0.8: 1 and 1: 1.2, preferably between

0.9: 1 and 1.1: 1, more preferable between 0.95: 1 and 1.05: 1.

In the case of one-component coating compositions, the selected isocyanate group-containing compounds (B) and optionally (BS) are those whose free isocyanate groups are blocked with blocking agents. Isocyanate groups can be blocked, for example, with substituted pyrazoles, more particularly with alkyl-substituted pyrazoles, such as 3-metylpyrazole, 3,5-dimethylpyrazole, 4-nter-3,510 dlmethylpyrazole, 4-bromo-3 , 5-dimethylprazole and so on. With particular preference the isocyanate groups of components (B1) and (B2) are blocked with 3,5-dimethylpyrazole.

In the case of inventively preferred 2-component (2K) coating compositions, a film-forming component comprising the hydroxyl-containing compound (A) and also other components, described below, is mixed, shortly before applying the composition coating, with another film-forming component, comprising the isocyanate group-containing compound (B) and, optionally, (BS) and, optionally, different from the components described below, mixing occurring in a conventional manner, with generally speaking - the film-forming component comprising compound (A) comprising the catalyst and also a portion of the solvent.

If desired, in addition to the hydroxyl-containing component (A), the coating compositions of the invention may comprise one or more hydroxyl-containing compounds (C), which are different from component (A). Preferably these compounds (C) account for a fraction of 10% to 50% by weight, more preferably 20% to 40% by weight, based on the non-volatile fraction of the polyol component (A) + (C).

As the hydroxyl-containing compound (C), use is made not only of low molecular mass polyols, but also of oligomeric and / or polymeric polyols other than component (A).

The low molecular mass polyols used are, for example, diols, such as, preferably, ethylene glycol, neopentyl glycol, 1,2-propanediol, 2,2-d-met i-1,3-propa nod iol, 1,4-butanediol , 1,3-butanediol, 1,5-pentanediol, 2,2,4 -1 rimeti I -1,3-pentanediol, 1,615 hexanediol, 1,4-cyclohexanedimethanol and 1,2-cyclohexanedimethanol, and also polyols, such as preferably, tri-methyl-methylol, trimethylolpropane, trimethylolhexane, 1,2,4-butanetriol, pentaerythritol and di-pentaerythritol.

Low molecular weight polyols of this class are preferably mixed in minor proportions to the polyol component (A).

The oligomeric and / or polymeric polyols (C) used are, for example, polyester polyols, polyurethane polyols and polysiloxane polyols, when component (A) is composed exclusively of polyacrylate polyols and / or polymethacrylate polyols.

Catalyst (D)

The coating compositions of the invention preferably comprise at least one catalyst (D) for the crosslinking of the silane groups. Examples are metal complexes with zinc or aluminum based chelate ligands, such as the titanates or Lewis acids described in WO 05/03340, for example; however, when selecting catalysts, care must be taken to ensure that the catalysts do not lead to yellowing of the coating compositions. Furthermore, a number of catalysts known to be used are less desirable, on toxicological grounds.

Therefore, it is preferred as catalyst (D) to use phosphorous-containing catalysts, more in particular phosphorous-containing and nitrogen-containing catalysts. In this context, mixtures of two or more different catalysts (D) can also be used.

Examples of suitable phosphorous-containing catalysts (D) are substituted phosphonic diesters and diphosphonic diesters, preferably from the group consisting of acyclic phosphonic diesters, cyclic phosphonic diesters, acyclic diphosphonic diesters, and cyclic diphosphonic diesters. Catalysts of this class are described in German patent application DE-A-102005045228, for example.

However, in particular the substituted phosphoric monoesters and phosphoric diesters are used, preferably from the group consisting of acyclic phosphoric diesters and cyclic phosphoric diesters, more preferably amine adducts of the phosphoric monoesters or diesters.

Very particular preference is given to using, as catalyst (D), the corresponding amine-blocked phosphoric esters, and of these, more particularly, amine-blocked phosphoric acid ethylhexyl esters and amine-blocked phosphoric acid esters of especially preferably, b i (2-eti I he xi I) amine-blocked phosphoric acid esters.

Particular examples of amines with which the phosphoric esters are blocked include tertiary amines, examples being bicyclic amines, such as, for example, diazabicyclooctane (DAB.CO); diazabicylononene (DBN), diazabicycloundecene · (DBU), dimethyldodecylamine or triethylamine. Tertiary amines are preferred for blocking phosphoric esters in particular, which ensure high catalyst activity under the curing conditions of

140 ° C.

Particular amine-blocked phosphoric acid catalysts are also commercially available (eg, Nacure products from King Industries). For example, mention may be made of King Industries' Nacure 4167 as a particularly suitable catalyst based on a phosphoric acid amine blocked partial ester.

The catalysts are preferably used in fractions of

0.01% to 20%, more preferable in fractions of 0.1% to 10% by weight, based on the non-volatile constituents of the coating composition of the invention. The lower activity in the catalyst part can be partially compensated by correspondingly higher amounts used.

The coating compositions of the invention may further comprise another amine catalyst based on a bicyclic amine, more particularly on an unsaturated bicyclic amine.

Examples of suitable amine catalysts are 1,5biazabicyclo [4.3.0] non-5-ene or 1,8-diazabicyclo [5.4.0] undec-7-ene.

These amine catalysts are preferably used in fractions of 0.1% to 10% by weight, based on the non-volatile constituents of the coating composition of the invention.

Suitable solvents for the compositions. coating compounds of the invention are more particularly those which within the coating composition are chemically inert towards compounds (A), (B) and, where used, (C), and which also do not react with ( A) and (B) during the cure of the coating composition. Examples of such solvents are aliphatic and / or aromatic hydrocarbons such as toluene, xylene, naphtha solvent, Solvesso 100 or Hydrosol® (from ARAL), ketones such as acetone, methyl ethyl ketone or methyl amyl ketone, esters, such as acetate of ethyl, butyl acetate, pentyl acetate or ethyl ethoxypropionate, ethers, or mixtures of the aforementioned solvents. Aprotic solvents or solvent mixtures preferably have a water content of not more than 1% by weight, plus 5 in particular not more than 0.5% by weight, based on the solvent.

Apart from compounds (A), (B) and, where used, (C) it is also possible to use more binders (E) as well, which can preferably react with the hydroxyl groups of poly (meth) acrylate (A) and / or with the free isocyanate groups of compound (B) and / or with the alkoxysilyl groups of compounds (B) and / or (C) and to form network nodules.

As component (E) it is possible, for example, to use amino resins and / or epoxy resins. Suitable amino resins include the usual and known amino resins, some of which 15 methylol and / or methoxymethyl groups may have been de-functionalized by carbamate or .allophanate groups.

Interlocking agents of this class are described in US-A-4 71 0 542 and EP-B-0 245 700 and also in the article by B. Singh et al., "Carbamylmethylated Melamines,

Novel Crosslinkers for the Coatings Industry ”, in Advanced Organic Coatings Science and Technology Series, 1991, volume 13, pages

193 to 207.

Generally speaking, said components (E) are used in fractions of up to 40%, preferably up to 30%, more preferably up to 25%, by weight, based on the non-volatile constituents of the coating composition.

Furthermore, the binder mixture of the invention or the coating composition of the invention can comprise at least one customary and known coating additive (F) in effective amounts, i.e. in amounts preferably up to 30%, more preferably up to 25%. %, and more particularly up to 20% by weight, based in each case on the non-volatile constituents of the coating composition.

Examples of suitable coating additives (F) are as follows:

in particular, UV absorbers;

in particular light stabilizers such as compounds of

-. HALS, benzotriazoles or oxalanilides;

- free radical sweepers;

runoff additives; polymerization inhibitors; defoamers;

reactive diluents, of the kind which are generally known in the prior art, and which are preferably inert towards the -Si (OR) groups₃;

humidifying agents such as siloxanes, fluorine compounds, carboxylic monoesters, phosphoric esters, polyacrylic acids and copolymers thereof or polyurethanes;

- adhesion promoters such as tricyclodecanedimethanol;

flow control agents;

film forming assistants such as cellulose derivatives;

fillers such as, for example, nanoparticles based on silicon dioxide, aluminum oxide or zirconium oxide; for more details refer to Rómpp Lexikon “Lacke und Druckfarben”, Georg Thieme Verlag, Stuttgart, 1 998, pages 250 to 252; Rheology contri additives, such as the known additives from WO 94/22968, EP-A-0 276 501, EPA-0 249 201 or WO 97/1 2945; entangled polymeric microparticles, of the class described, for example, in EP-A-0 008

127; inorganic phyllosilicates such as aluminum magnesium silicates, sodium magnesium phyllosilicates and sodium magnesium fluorine lithium phyllosilicates of the montmorillonite type; silicas such as Aerosils®; or synthetic polymers containing ionic and / or associative groups, such as polyvinyl alcohol, poly (meth) acrylamide. Poly (meth) acrylic acid, poIiviniIpirroIidone, styrene-maleic anhydride or copolymers of ethylene-maleic anhydride and its derivatives, or hydrophobically modified ethoxylated urethanes or polyacrylates;

flame retardants; and / or water sweepers.

In another embodiment of the invention, the binder mixture or coating composition of the invention may also comprise other pigments and / or fillers and may serve for the production of pigmented paint coats. The pigments and / or fillers used for this purpose are known to the person skilled in the art.

The coatings of the invention which are produced from the coating compositions of the invention adhere excellently even to conventional and known conventionally cured electrolayers, surface layers, base coats or clearcoats, and are remarkably suitable as well as for use in automotive OEM (production line) finish, for automotive restoration and / or for coating components for installation in or on automobiles, or for the modular scratch resistance of automotive bodies that have already been completed.

The coating compositions of the invention can be applied by any of the customary application methods, such as spraying, knife coating, smearing, pouring, dipping, impregnating, dripping or rolling, for example. In application, the substrate to be coated may be at rest, with the application or installation device being moved.

Alternatively, the substrate to be coated, more particularly a coil, may be in motion, with the application equipment being at rest relative to the substrate or being moved in an appropriate manner.

It is preferred to employ spray application methods, such as, for example, compressed air spray, airless spray, high speed rotation, electrostatic spray application (ESTA), alone or in conjunction with hot spray application such as hot air, for example.

Curing of the applied coating compositions of the invention can occur after a certain amount of rest. The standing time is used, for example, for leveling and devolatilization of the coating films, or for the evaporation of volatile constituents such as solvents. The dwell time can be assisted and / or shortened through the application of elevated temperatures and / or through a reduced atmospheric humidity, as long as it does not imply any damage or change to the covering films, such as premature complete entanglement, for example.

Thermal curing of the coating compositions has no method peculiarities but instead occurs according to customary and known methods such as heating in a forced air oven or irradiation using IR lamps. This thermal cure can also occur in stages. Another preferred cure method is that of near infrared radiation (NIR radiation) cure.

Thermal curing advantageously occurs at a temperature of 30 to 200 ° C, more preferably 40 to 190 ° C, and more particularly 50 to 180 ° C, for a time of 1 minute to 10 hours, more preferably 2 minutes to 5 hours, and more particularly 3 minutes to 3 hours; At temperatures used for automotive restoration and for coating plastic parts, which are preferably between 30 to 90 ° C, it is also possible to use longer cure times.

The coating compositions of the invention show high solids content and provide new cured coatings, more particularly coating systems, especially clearcoat systems, molds, especially optical molds, and self-supporting sheets that are highly resistant to scratches, even after long-term exposure. At the same time, the coatings obtained in accordance with the invention also have a very good overall appearance. Finally, the coatings and coating systems of the invention, especially clearcoat systems, can be produced even at film thicknesses> 40 pm without stress cracking occurring.

The coating compositions of the invention are therefore notoriously suitable as highly scratch-resistant, decorative, protective and / or effect-imparting coatings and coating systems on transport bodywork (more particularly motor vehicles, such as motorcycles, buses, trucks, or automobiles) or parts thereof; of buildings, inside and outside; furniture, windows and doors;

of plastic molds, more particularly CDs and windows; small industrial parts, coils, containers and packaging; household appliances; of movies; of optical, electrical and mechanical components; and also hollow glassware and everyday items.

More in particular, the coating compositions and coating systems of the invention, especially the transparent coatings, are employed in the particularly technologically and aesthetically demanding field of automotive OEM finishing for the coating of plastic parts for installation in or on automotive bodies, in particular for high-class automotive bodies, such as, for example, for the production of roofs, trunks, chests, facías, fenders, spoilers, running boards, side strips, side upholstery, and so on, and also for automotive restoration.

The plastic parts are typically composed of ASA, polycarbonates, mixtures of ASA and polycarbonates, polypropylene, polymethyl methacrylates or impact modified polymethyl methacrylates, more particularly mixtures of ASA and polycarbonates, preferably used with a polycarbonate fraction> 40 %, more particularly> 50%.

By ASA is meant, in general, impact modified styrene / acrylonitrile polymers wherein the graft copolymers of vinyl aromatic compounds, especially styrene, and vinyl cyanides, especially acrylonitrile, are present in a polyalkyl acrylate rubber. copolymeric matrix comprising, in particular, styrene and acrylonitrile.

With particular preference, the coating compositions of the invention are employed in multistage coating processes, more particularly in processes where an optionally precoated substrate is first coated with a pigmented base coat, after which a coat is applied with the coating composition of the invention. Accordingly, the invention also provides multi-layer color and / or effect paint systems comprising at least one pigmented base coat and at least one clear coat disposed therein, characterized in that the clear coat has been produced from the coating composition of the invention.

Not only can water dilutable basecoats be used, but organic solvent based basecoats as well. Suitable basecoat materials are described, for example, in EP-A-0 692 007 and in the documents listed there in column 3, lines 50ff. Preferably, the applied basecoat material is first dried, meaning that the basecoat film, in an evaporation phase, has at least some of the organic solvent and / or water removed therefrom. Drying preferably occurs at room temperature temperatures of 80 ° C. After drying, the coating composition of the invention is applied. The two-layer system is subsequently baked preferably under conditions that are employed in the context of automotive OEM finishing, at temperatures of 30 to 200 ° C, more preferably 40 to 190 ° C, and more particularly 50 to 180 ° C , for a time of 1 minute to 10 hours, more preferably 2 minutes to 5 hours, and more particularly 3 minutes to 3 hours; At the temperatures used for automotive restoration, which are preferably between 30 and 90 ° C, longer cure times can also be used.

In another preferred embodiment of the invention, the coating composition of the invention is used as a clear clearcoat material for coating plastic substrates, more particularly plastic parts for installation in or on a vehicle. These parts are preferably also coated in a multi-stage coating method, wherein an optionally pre-coated substrate or a pre-coated substrate for improved adhesion of the subsequent layers (eg, by flame, corona or plasma treatment of the substrate) is first coated with a pigmented base coat, after which a coat with the coating composition of the invention is applied.

Finally, the coating composition of the invention is used as a clear clearcoat material to coat clear plastic substrates. In this case, the coating compositions comprise UV absorbers which in terms of their quantity and type are designed for effective UV protection of the plastic substrate.

EXAMPLES

Preparation of a poly (meth) acrylate resin with hydroxyl groups (A1)

A double-walled 4-liter stainless steel tank that can be heated by an air circulation thermostat and is equipped with a thermometer, anchor stirrer, 2 burettes, and flow condenser is charged with solvent for polymerization. One of the burettes is loaded with the monomer mixture, the second burette with the initiator solution, comprising a suitable initiator (usually a peroxide). The initial charge is heated to a polymerization temperature of 140 ° C. When the polymerization temperature is reached, the initiator feed begins first. 15 minutes after the start of the initiator feed, the monomer feed begins (duration: 240 minutes). The initiator feed is set to continue for 30 minutes after the end of the monomer feed. After the end of the starter feed, the mixture is stirred at 140 ° C for an additional 2 hours and then cooled to room temperature. The reaction mixture is subsequently adjusted with solvent to the solids content specified in Table 2.

Table 1: Composition of polymethacrylate (A1) in parts by weight

<td>Component</td><td>Part (s) by weight</td>

<td>Styrene</td><td> 8.0</td>

<td>n-Butyl methacrylate</td><td> 8.0</td>

<td>Acrylic acid</td><td> 0.6</td>

<td>4-Hydroxybutyl acrylate</td><td> 1 2.0</td>

<td>2-Hydroxybutyl acrylate</td><td> 12.0</td>

<td>n-Butyl acrylate</td><td> 19.0</td>

Table 2: Characteristics of polymethacrylate (A1) (acid number and viscosity determined experimentally, number of OH and Tg calculated theoretically)

<td>Solids 1h 150 ° C</td><td> 65%</td>

<td>Acid No. (measured)</td><td> 8-12</td>

<td>[mg KOH / g]</td><td></td>

<td>OH number calculated</td><td> 175</td>

<td>[mg KOH / g]</td><td></td>

<td>Tg (FOX) [° C]</td><td> -27</td>

<td>Viscosity [mPa.s] ¹⁾</td><td> 2200</td>

determined at room temperature to DIN53229 with a Brookfield cone 10 / plate viscometer, cone 3

Preparation of a low viscosity poly (meth) acrylate resin, modified with caprolactone with hydroxyl groups (A2)

A stainless steel stirring vessel with anchor stirrer and reflux condenser is charged with 290 g of butyl acetate and 290 g of naphtha solvent, and this initial charge is heated to 167 ° C under a nitrogen atmosphere and with stirring, at a pressure of 3.5 bar absolute. A solution of 288.8 g of di-ter-amyl peroxide and 10.7 g of butyl acetate and 10.8 g of naphtha solvent is added dropwise over the course of 275 minutes. The monomer mixture of 400 g of styrene, 550 g of butyl methacrylate, 803.3 g of hydroxyethyl acrylate, 550 g of ethylhexyl acrylate, and 102.9 g of acrylic acid is added as toas at a uniform rate over the course 240 minutes. The monomer feed begins 5 minutes after the initiator feed. After the end of the feeds, the reactor contents are held at 167 ° C for an additional 20 minutes and then 993 g of caprolactone are measured over the course of an hour, during which the reactor temperature is uniformly reduced to 150 ° C. After the end of the feeding, stirring continues at 150 ° C for 1.5 hours. Then, the contents of the reactor are cooled, the pressure is lowered to a temperature below 121 ° C, and, at 80 ° C, the reactor is emptied. The resulting polymer solution has an 81.2% solid with a viscosity of 2400 mPa.s. The binder has an average mass molar mass of 5,300 g / mol with a polydispersity of 3.0 (determined by GPC versus polystyrene calibration).

Table 3: Composition of polymethacrylate (A2) in parts by weight

<td>Component</td><td>Parts by weight</td>

<td>Styrene</td><td> 16.6</td>

<td>n-Butyl methacrylate</td><td> 22.9</td>

<td>Acrylic acid</td><td> 4.3</td>

<td>Ethylhexyl acrylate</td><td> 22.9</td>

<td>2-Hydroxyethyl acrylate</td><td> 3 3.4</td>

Table 4: Characteristics of polymethacrylate (A2) (number of 10 experimentally determined acid, number of experimentally determined OH)

<td></td><td>A2</td>

<td>Solids [%] (1 hr 130 ° C)</td><td> 81 .2</td>

<td>Acid number [mg KOH / g]</td><td> 27.6</td>

<td>OH number [mg KOH / g]</td><td> 122</td>

<td>Viscosity [mPa.s] ¹¹</td><td> 2400</td>

determined at room temperature to DIN53229 with a cone

Brookfield / plate viscometer, cone 3

Preparation of an inventive curing agent (B1) based on a dimeric uretdione, based on HDI (10 mol% of monosilane structures and 90 mol% of structures of bis i la no Illa: degree of conversion of isocyanate groups c = 40 mol%)

A steel reactor equipped with a reflux condenser and a thermometer is charged with 48.3 parts of dichlorinated hexamethylenedisocyanate (HDI) containing uretdione groups (Desmodur N3400 from Bayer), 12.1 parts of butyl acetate, and 2.4 parts of trietllo orthoformate. . From a burette, a mixture of 30.7 parts of b¡ [3- (tri m etox ¡s ¡I ¡I) p rop ¡l] ami na (Dynasylan 1124,

Evonik, Rhelnfelden) and 2.4 parts of trlmetoxisiülpropü-n-butylamine (Dynasylan 1189, Evonik, Rheinfelden) are then added dropwise under nitrogen inerting and with stirring. A slight increase in temperature is observed at around 40 ° C. After 2 hours of stirring, the NCO value is determined by filtration: NCO content: 6.6% (solution). The non-volatile fraction (1 hr, 150 ° C) is 8 5%.

Preparation of a non-inventive curing agent (BV1) based on isocyanurate based on narrow distribution HDI (10 mol% of monosilane ly structures and 90 mol% of Illa bisilane structures: degree of conversion of isocyanate groups 5 c = 40% molar)

A steel reactor equipped with a reflux condenser and a thermometer is charged with 57.6 parts of dimerized hexamethylene diisocyanate (HDI) (Desmodur N3600 from Bayer), 14.8 parts of butyl acetate, and 2.4 parts of triethyl orthoformate.

From a burette, a mixture of 39.4 parts of bi [3 (trimethoxisi I i I) propi I jamina (Dynasylan 1124, Evonik, Rheinfelden) and 3.0 parts of trímetoxis¡lilprop¡ln-butilam¡na (Dynasylan 1189,

Evonik, Rheinfelden) is then added dropwise under nitrogen blanketing and with stirring. A slight increase in temperature is observed at around 40 ° C. After 2 hours of stirring, the NCO value is determined by titration: NCO content: 6.6% (solution). The non-volatile fraction (1 hr, 150 ° C) is 85%.

Preparation of a non-inventive curing agent (BV2) based on wide distribution HDI-based isocyanurate (10 mol% of monosilane ly structures and 90 mol% of Illa bisilane structures: degree of conversion of isocyanate groups c =

40% molar)

A steel reactor equipped with a reflux condenser and a thermometer is charged with 67.6 parts of dimerized hexamethylene diisocyanate (HDI) containing uretdione groups (Desmodur N3300 from Bayer), 16.9 parts of butyl acetate, and 3.4 parts of triethyl orthoformate . From a burette, a mixture of

43.0 parts of bi [3 - (trimethoxysi I i I) propi I] amine (Dynasylan 1124, Evonik, Rhelnfelden) and 3.3 parts of trimethoxysiIIpropiI-n-butiIamine (Dynasylan 1189, Evonik, Rheinfelden) is then added in the form of drops under inerting with nitrogen and with agitation. A slight increase in temperature is observed at around 40 ° C. After 2 hours of stirring, the NCO value is determined by titration: NCO content: 6.6% (solution). The non-volatile fraction (1 hr, 150 ° C) is 8 5%.

Formulation of the inventive coating compositions B1 and B2 and the coatings of inventive examples 1 and 2, and of coating compositions CB1 to CB4 of comparative examples C1 to C4, and the coatings of comparative examples C1 to C4

In the order listed (starting from the top), the constituents listed in Table 5 and Table 6 are combined intimately with each other in an appropriate container and immediately afterwards coated on a black basecoated metal mirror plate (basecoat drying : 30 minutes at 80 ° C, evaporation time of 10 minutes). The leaves are then dried in an oven at 60 ° C for 30 minutes. The coatings obtained are stored at room temperature for 24 hours and subjected to measurement with a BYK-Gardner Wave-Scan®. The test results are set forth in Table 7 and Table 8.

Table 5: Composition of the inventive coating composition B1 and of the coating compositions CB1 and CB2 of comparative examples C1 and C2, in each case based on the hydroxyl-containing polymethacrylate (A1)

<td></td><td>Example B1</td><td>Example comp. CB1</td><td>Example comp. CB2</td>

<td>Polyacrylate (A1)</td><td> 40</td><td> 40 -</td><td> 40</td>

<td>Dynoadd F1 ¹⁾</td><td> 0.2</td><td> 0.2</td><td> 0.2</td>

<td>Tinuvin® 384 ^{2) *}</td><td> 0.5</td><td> 0.5</td><td> 0.5</td>

<td>Tinuvin® 292 ^3&gt;</td><td> 0.5</td><td> 0.5</td><td> 0.5</td>

<td>Acetate of butilo</td><td> 8</td><td> 8</td><td> 8</td>

<td>Nacure 4167® ⁴⁾</td><td> 1.2</td><td> 1.2</td><td> 1.2</td>

<td>Curing agent B1</td><td> 50</td><td></td><td></td>

<td>BV1 Curing Agent</td><td></td><td> 50</td><td></td>

<td>(comp.)</td><td></td><td></td><td></td>

<td>BV2 Curing Agent</td><td></td><td></td><td> 50</td>

<td>(comp.)</td><td></td><td></td><td></td>

<td>Non-volatile fraction (1 h,</td><td> 70%</td><td> 7 0%</td><td> 70%</td>

<td>150 ° C)</td><td></td><td></td><td></td>

Dy * Dynoadd F1 = commercial, multifunctional, surface active additive from HertfelderGmbH, Bielefeld ²⁾ Tinuvin® 384 = commercial light stabilizer based on a benzotriazole, from Ciba ³⁾ Tinuvin® 292 = commercial light stabilizer based on a spherically hindered amine, from Ciba ⁴⁾ Nacure® 4167 = commercial amine-blocked phosphoric acid partial ester based catalyst from King Industries, non-volatile fraction 25%

Table 6: Composition of coating compositions B2, CB3 and CB4, in each case based on hydroxyl-containing polymethacrylate, modified with caprolactone (A2)

<td></td><td>Example B2</td><td>Example comp. CB3</td><td>Example comp. CB4</td>

<td>Polyacrylate (A2)</td><td> 41</td><td> 41</td><td> 41</td>

<td>Dynoadd F1 ¹ &gt;</td><td> 0.2</td><td> 0.2</td><td> 0.2</td>

<td>Tinuvin® 384 ²⁾</td><td> 0.5</td><td> 0.5</td><td> 0.5</td>

<td>Tinuvin® 292 ³⁾</td><td> 0.5</td><td> 0.5</td><td> 0.5</td>

<td>Acetate of butilo</td><td> 8</td><td> 8</td><td> 8</td>

<td>Nacure 4167® ⁴⁾</td><td> 1</td><td> 1</td><td> 1</td>

<td>Curing agent B1</td><td> 45</td><td></td><td></td>

<td>BV1 Curing Agent</td><td></td><td> 45</td><td></td>

<td>(comp.)</td><td></td><td></td><td></td>

<td>BV2 Curing Agent</td><td></td><td></td><td> 45</td>

<td>(comp.)</td><td></td><td></td><td></td>

<td>Non-volatile fraction (1h,</td><td> 7 5%</td><td> 7 5%</td><td> 7 5%</td>

<td>150 ° C)</td><td></td><td></td><td></td>

Table 7: Test results for coatings

<td rowspan="2"></td><td rowspan="2">Sheet base coat 1 without layer clear</td><td rowspan="2">Example B1 in sheet of base coat one</td><td rowspan="2">Sheet base coat 2 without c apa clear</td><td colspan="2">Ex Comp. C B1 in sheet of</td><td rowspan="2">Sheet base coat 3 without cape clear</td><td rowspan="2">Ex Comp. C B2 in sheet of base coat 3</td>

<td>cap 2</td><td>base</td>

<td>FT (pm)</td><td> 1 5</td><td> 39</td><td> 1 5</td><td colspan="2"> 41</td><td> 1 6</td><td> 39</td>

<td>SW</td><td> 8.0</td><td> 1 .7</td><td> 8.1</td><td colspan="2"> 10.3</td><td> 7.8</td><td> 85.4</td>

<td>LW</td><td> 2.4</td><td> 2.2</td><td> 2.6</td><td colspan="2"> 14.6</td><td> 2.4</td><td> 60.3</td>

Table 8: Test results for the coatings of inventive example 2 and for the coatings of comparative examples C3 and C4

<td></td><td>Sheet</td><td>Ex em p I o</td><td>Sheet</td><td>Eg Com p.</td><td>Sheet</td><td>Ex Comp.</td>

<td></td><td>base coat</td><td>B2 in</td><td>base coat</td><td>C B3 in</td><td>base coat</td><td>CB4 in</td>

<td></td><td>4 without cape</td><td>sheet of</td><td>5 without cape</td><td>sheet of</td><td>6 without cape</td><td>sheet of</td>

<td></td><td>clear</td><td>base coat</td><td>clear</td><td>base coat</td><td>clear</td><td>base coat</td>

<td></td><td></td><td> 4</td><td></td><td> 5</td><td></td><td> 6</td>

<td>FT (pm)</td><td> 1 5</td><td> 39</td><td> 1 5</td><td> 41</td><td> 1 7</td><td> 39</td>

<td>SW</td><td> 8.3</td><td> 1.6</td><td> 8.1</td><td> 9.7</td><td> 8.7</td><td> 18.9</td>

<td>LW</td><td> 2.4</td><td> 0.7</td><td> 2.2</td><td> 21.3</td><td> 2.2</td><td> 25.5</td>

All coatings are dry to the touch after described drying (30 minutes at 60 ° C). Any incidence of sticky films under abnormal optimal laboratory conditions can be easily remedied by slightly increased amounts of catalyst and / or more effective catalysts.

Summary of test results:

Comparison of both the long-wave (LW) and short-wave (SW) values ​​in Table 7 for Inventive Example 1 with those for Comparative Example C1 and Comparative Example C2 shows that Inventive Example 1 exhibits values ​​substantially better than comparative examples C1 and

C2, that is, the inventive coating composition B1 exhibits substantially better flux than the coating compositions of Comparative Examples C1 and C2.

Similarly, comparison of both the longwave (LW) and the shortwave (SW) values ​​in Table 8 for Inventive Example 2 with those for Comparative Example C3 and Comparative Example C4 also shows that Example Inventive 2 exhibits substantially better values ​​than Comparative Examples C3 and C4, i.e. that inventive coating composition B2 exhibits substantially better flow than the coating compositions of Comparative Examples C3 and

C4.

Furthermore, through a comparison of inventive coating composition B1 with inventive coating composition B2, it is evident that with a caprolactone modified binder (A2), the non-volatile fraction of the coating composition can be further increased and that the coating

<td>resulting</td><td>of the</td><td>example B2, a</td><td colspan="2">despite the non-volatile fraction</td>

<td>increased</td><td>of</td><td>the composition</td><td>B2 coating,</td><td>exhibits a</td>

<td colspan="2">10 optical quality</td><td>whose attraction</td><td>is consistent with</td><td>that of</td>

coating of example 1.

Preparation of an inventive curing agent (B2) based on a dimeric uretdione based on HDI (20 mol% of monosilane ly structures and 80 mol% of bisilane structures Illa: degree of conversion of isocyanate groups c = 40% cool)

A steel reactor equipped with a reflux condenser and a thermometer is charged with 50 parts dimerized hexamethylene diisocyanate (HDI) containing uretdione groups (Desmodur N3400 from Bayer), 16 parts butyl acetate, and 3 parts triethyl orthoformate . From a burette, a mixture of parts of b¡ [3 - (tr me to xis il I) p ro pi I] amine (Dynasylan 1124, Evonik, Rheinfelden) and 8 parts of trimethoxysilylpropyl-n-butylamine (Dynasylan 1189 , Evonik, Rheinfelden) is then added dropwise under nitrogen blanketing and with stirring. A slight increase in temperature is observed at around 40 ° C. After 2 hours of stirring, the NCO value is determined by titration. Non-volatile fraction (1 hr, 150 ° C): 80%,

NCO content: 6.1% (solution).

Preparation of an isocyanate curing agent containing isocyanurate group (BS1) parts by weight of a commercial trimerized polyisocyanate containing isocyanurate groups and based on hexamethylene diisocyanate (Desmodur® N3600 from Bayer) and 10 parts of butyl acetate are mixed together by stirring to give a solution having a solids content of 80.0% by weight.

Preparation of an inventive curing agent (BS2) containing an isocyanurate group based on a HDI-based trimeric isocyanurate (20 mol% of monosilane ly structures and 80 mol% of bisilane structures Illa: degree of conversion of isocyanate groups c = 40 mol%)

A steel reactor equipped with a reflux condenser and a thermometer is charged with 50 parts dimerized hexamethylene diisocyanate (HDI) containing uretdione groups (Desmodur N3600 from Bayer), 16 parts butyl acetate, and 3 parts triethyl orthoformate . From a burette, a mixture of 24 parts of bi [3 - (tr methoxis I i I) propi I] am (Dynasylan 1124, Evonik, Rheinfelden) and 8 parts of tr¡metox¡s¡IiIprop¡In -butylamine (Dynasylan 1189, Evonik, Rheinfelden) is then added dropwise under nitrogen inerting and with stirring. A slight increase in temperature is observed at around 40 ° C. After 2 hours of stirring, the NCO value is determined by titration. Non-volatile fraction (1 hr, 150 ° C): 80%,

NCO content: 6.3% (solution).

By mixing the amounts indicated in Table 9 of the silanized uretdione (B2) and isocyanurate group-containing isocyanate (BS1) or (BS2), respectively, the H1 and H2 curing agent mixtures listed in Table 9 are produced.

Table 9: Composition in parts by weight, solids content, isocyanate content, and viscosity of the curing agent mixtures H1 and H2

<td>Mix of</td><td>U reta-</td><td>Isocyanu-</td><td>Isocyanu-</td><td>B2: BS</td><td>Content of</td><td>Solids</td><td>Viscosity</td>

<td>agent of</td><td>diona B2</td><td>while BS 1</td><td>BS2 time</td><td>in %</td><td>isocyanate</td><td>of the</td><td>[mPa.s]</td>

<td>healing</td><td></td><td></td><td></td><td>in</td><td>mix [%]</td><td>mixture</td><td></td>

<td></td><td></td><td></td><td></td><td>weight</td><td></td><td> [%]</td><td></td>

<td>H1</td><td> 50</td><td> 50</td><td></td><td> 50:50</td><td> 12.0</td><td> 80</td><td> 87</td>

<td>H2</td><td> 50</td><td></td><td> 50</td><td> 50:50</td><td> 6.6</td><td> 80</td><td> 166</td>

Calculation of the ratios of the uretdione group-containing compound B2 to the isocyanurate group-containing compound BS1 or BS2 in equivalents for the curing agent mixtures H1 and H2

Calculation of the equivalent weight of Desmodur® N3400 according to the technical data sheet: (100 * 42 g) /21.8 = 193 g

Calculation of the equivalent weight of Desmodur® N3600 according to the technical data sheet: (100 * 42 g) / 23 = 183 g

Calculated equivalent weight of bi [3- (tr ¡m et oxisi I i I) propi I] am ¡na:

341 g

Calculated equivalent weight of trmetoxisiI¡IpropiI-n-butiIamina:

2. 3. 4 g

Calculation of the equivalent weight for the compound containing uretdione group B2:

Conversion rate c in B2 to silane units: 40 mole%

As2 fraction in B2 of the isocyanate groups reacted with monosilane: (amount of monosilane in molar%) / [total fraction (monosilane + bisilane) = 100% molar] = 0.2

As3 fraction in B2 of the isocyanate groups reacted with bisilane: (amount of bisilane in mol%) / [total fraction (monosilane + bisilane) = 100 mol%] - 0.8

Equivalent weight for compound B2 containing uretdione group: [193 g (equivalent weight of Desmodur® N3400)] +

0.4 * [(0.2 * 234 g) + (0.8 * 341 g)] = 321 g

Calculation of the equivalent weight for the compound containing group isocyanurate group BS1:

Degree of conversion c 'in BS1 to silane units; 0% molar

As'2 fraction in BS1 of the isocyanate groups reacted with monosilane: (amount of monosilane in molar%) / [total fraction (monosilane + bisilane) = 100% molar] = 0

As'3 fraction in BS1 of the isocyanate groups reacted with bisilane: (amount of bisilane in mol%) / [total fraction (monosilane + bisilane) = 100 mol%) = 0

Equivalent weight for compound BS1 containing isocyanurate group: [183 g (equivalent weight of Desmodur © N3600)] + 0 * [(0 * 234 g) + (0 * 341 g)] = 183 g

Calculation of the equivalent weight for the compound containing the isocyanurate group BS2:

Conversion rate c 'in BS2 to silane units: 40 mol%

As'2 fraction in BS2 of the isocyanate groups reacted with monosilane: (amount of monosilane in molar%) / [total fraction (monosilane + bisilane) = 100% molar] = 0.2

As'3 fraction in BS2 of the isocyanate groups reacted with bisilane: (amount of bisilane in mol%) / [total fraction (monosilane + bisilane) = 100 mol%] = 0.8

Equivalent weight for compound B2 containing isocyanurate group: [183 g (equivalent weight of Desmodur® N3600)] + 0.4 * [(0.2 * 234 g) + (0.8 * 341 g)] = 311 g

Calculation of the ratio of the H1 curing agent mixture

<td>(50 parts by weight</td><td>of compound B2 and</td><td>50 parts in</td><td>weight of</td>

<td>compound BS1) in</td><td>B2 equivalents</td><td>to equivalents</td><td>from BS1:</td>

<td> 1.0:1.75</td><td></td><td></td><td></td>

<td>B2 equivalents</td><td> 50/321</td><td> 1 83</td><td> 1.0</td>

<td>BS1 equivalents</td><td> 50/183</td><td> 321</td><td> 1.75</td>

Calculation of the ratio of the curing agent mixture H2 (50 parts by weight of compound B2 and 50 parts by weight of compound BS2) in equivalents of B2 to equivalents of BS2:

1.0:1.03

B2 equivalents 50/321 50 * 31 1 1.0

BS2 equivalents

50/311

50*321

1.03

Formulation of the inventive coating compositions

B3 and B4 and the coatings of inventive examples 3 and 4

In the order listed (starting from the top), the 5 constituents listed in Table 10 are intimately combined with each other in an appropriate container and immediately afterwards coated on a metallic mirror plate covered with black basecoat (basecoat drying: 30 minutes at 80 ° C, evaporation time of 10 minutes). The leaves are then dried in an oven at 60 ° C for 30 minutes. The coatings obtained are stored at room temperature for 24 hours and are measured with a BYK-Gardner Wave-Scan®. The test results are set forth in Table 11.

fifteen. Table 10: Composition of the inventive coating compositions B3 and B4, in each case based on the hydroxyl-containing polymethacrylate (A1)

<td></td><td>Example B3</td><td>Example B4</td>

<td>Polyacrylate (A1)</td><td> 95</td><td> 95··</td>

<td>Byk 333 ¹⁾</td><td> 0.4</td><td> 0.4</td>

<td>Tinuvin® 384 ²⁾</td><td> 1.0</td><td> 1.0</td>

<td>Tinuvin® 292 ³⁾</td><td> 1.0</td><td> 1.0</td>

<td>Nacure 41 67® ⁴⁾</td><td> 2.6</td><td> 2.6</td>

<td>H1 healing agent</td><td> 65</td><td></td>

<td>H2 curing agent</td><td></td><td> 1 20</td>

<td>Non-volatile fraction (1 h, 1 5 0 ⁰ C)</td><td> 70.9</td><td> 73.2</td>

<td>Acetate of butilo</td><td> 2</td><td> 1 0</td>

<td>Non-volatile fraction (1 hr, 150 ° C)</td><td> 70%</td><td> 70%</td>

¹⁾ Byk 333 = commercial, surface active additive of Byk Chemie ²⁾ Tinuvin® 384 = commercial light stabilizer based on a benzotriazole, from Ciba ³⁾ Tinuvin® 292 = commercial light stabilizer based on a spherically hindered 5 amine, from Ciba ⁴⁾ Nacure® 4167 = commercial amine-blocked phosphoric acid partial ester based catalyst from King Industries, non-volatile fraction 25%

Table 11: Test results for the coatings of Examples B3 and B4

<td></td><td>Layer Sheet base 1 without clear coat</td><td>Example B3 in sheet base layer 1</td><td>Layer Sheet base 2 without clear coat</td><td>Example B4 in sheet base layer 2</td>

<td>FT (pm)</td><td> 1 5</td><td> 40</td><td> 1 5</td><td> 40</td>

<td>SW</td><td> 8.0</td><td> 6.2</td><td> 8.0</td><td> 4.8</td>

<td>LW</td><td> 2.2</td><td> 1.2</td><td> 2.2</td><td> 1.4</td>

All coatings are dry to the touch after described drying (30 minutes at 60 ° C). Any incidence of sticky films under abnormal optimal laboratory conditions can be easily remedied by slightly increased amounts of catalyst and / or more effective catalysts.

Summary of test results:

With blends of inventive curing agent H1 and H2, therefore, very good leveling can be achieved at the target film thickness of 40, um, even with high solids content. In addition, inventive coating compositions ensure fast cure even under repair coat conditions, i.e. coatings are dry to the touch after dry to dry.

60 ° C for 30 minutes.