WO2010112157A1 - Protective paint - Google Patents

Abstract

The invention relates to coating agent having a high solids content, based on polyurea polymers, and to the use thereof as a protective finish paint.

Description

 protective lacquer

The invention relates to coating compositions with a high solids content based on polyurea polymers and their use as a protective topcoat.

Reaction products of aliphatic or cycloaliphatic polyamines with fumaric acid esters and / or maleic esters, so-called polyaspartic esters, are known as formulation constituents for low-solvent or -free two-component (2K) -polyurethane or polyurea lacquers.

As sterically hindered secondary amines have Polyasparaginsäureester, as described for example in EP-A 0 403 921 as Hauptbindemittel or as reactive diluents for hydroxy-functional lacquer binder, for aliphatic amines relatively moderate reactivity to aliphatic polyisocyanates, but still a rapid curing of the coatings even at low temperatures. With their help, hard and elastic coatings can be obtained, which are characterized by high resistance to abrasion and solvents as well as good weathering stability. Due to their low inherent viscosity, the use of polyaspartic acid esters in coating formulations significantly reduces volatile organic compound (VOC) content.

Coating compositions based on polyaspartic esters have been described for a large number of different applications, for example for vehicle repair and large vehicle painting (eg EP-A 0 470 461, EP-A 0 531 249, EP-A 1 581 575), which and textile coating (eg EP-A 1 277 876) or as a binder for electrical insulating lacquers (eg EP-A 1 199 320).

Polyaspartic esters have also been used as part of corrosion protection coatings. For example, EP-A 0 689 881 describes binder combinations with high solids contents of up to 95% by weight, which consist of polyaspartic esters, polyketimines or -aldimines and preferably aliphatic or cycloaliphatic lacquer polyisocyanates as crosslinking component, for coating steel parts.

Compared to conventional 2K-PUR systems, these polyol-free, pure polyurea systems lead to a noticeable increase in productivity for the user due to the very low solvent content and faster drying. To increase productivity, in addition to faster drying, it is essentially possible to apply thick layers free of bubbles in a single operation. Across from _ _

Conventional coating systems can therefore be achieved with less lacquer layers equal total thicknesses. Thus, in the case of a three-layer paint system, which usually consists of primer, intermediate layer and topcoat, for example, the intermediate layer can be dispensed with without sacrificing the quality of the coating. Compared to common two-layer corrosion protection coatings made of epoxy primer and polyurethane topcoat, the coating time can even be halved when using a monolayer topcoat system based on polyaspartic esters and polyisocyanates without the primer.

Despite the described ecological and economical advantages, such single-layer anticorrosive coatings could not prevail widely in practice. The reason for this lies in the insufficient adhesion of Polyasparaginsäureester systems on some special metallic substrates, such. As on aluminum, galvanized or cold rolled steel, which makes a primer layer indispensable.

It was therefore an object of the present invention to provide new high-solids 2K coating systems based on polyaspartic esters and polyisocyanate crosslinkers which have improved adhesion to critical metallic surfaces and thus permit direct application to unprimed materials. This problem could be solved by providing the coating agents described in more detail below.

The present invention therefore relates to coating compositions comprising A) at least one amine of the formula (I)

in which

X is an n-valent, isocyanate-inert radical, as obtained by removing the primary amino groups from an organic amine of the molecular weight range 60 to 6000 with n _

primary aliphatic and / or cycloaliphatic bound amino groups is obtained, which optionally contains one or more heteroatoms and / or further isocyanate-reactive and / or inert at temperatures up to 100 ° C functional groups,

R ¹ and R ^{2 are} identical or different organic radicals having 1 to 18 carbon atoms and n is an integer> 1,

B) optionally further isocyanate-reactive components, C) a silane-containing polyisocyanate component,

D) optionally organic solvents and

E) optionally further auxiliaries and additives, with the proviso that the components A), optionally B) and C) are present in proportions such that each isocyanate-reactive group of the components A) and optionally B) 0.7 to 2 , 0 isocyanate groups of the component

C) omitted.

The invention also relates to the use of these coating compositions for coating any substrates, in particular as corrosion protection topcoat.

The component A) present in the coating compositions of the invention are amines of the formula (I)

in which X is an n-valent, isocyanate-inert radical, as obtained by removing the primary amino groups from an organic amine in the molecular weight range 60 to 6000 with n primary aliphatic and / or cycloaliphatically bonded amino groups, optionally one or more heteroatoms and / or others, opposite I- _ _

contains socyanatgruppen reactive and / or inert at temperatures up to 100 ° C functional groups,

R ¹ and R ^{2 are} identical or different organic radicals having 1 to 18 carbon atoms and n is an integer> 1.

The preparation of such amines A) - hereinafter also referred to as aspartic acid esters or lyasparaginsäureester - is known in principle and may for example, as described in EP-A 0 403 921, EP-A 0 689 881 or EP-A 0 816 326, by Reaction of a component containing primary amino groups of the formula (II)

<+ NH, (H),

in which X and n have the abovementioned meaning, with fumaric acid esters and / or maleic acid esters of the formula (III)

R ¹ 0OC-CH = CH - COOR ² (III)

in which R 1 and R 2 have the abovementioned meaning, take place.

Suitable amines for the preparation of the polyaspartic esters A) are, for example, di-functional amines, ie. H. those of the formula (II) in which n is 2, such as. B. ethylene diamine, 1, 2-diaminopropane, 1, 4-diaminobutane, l, 5-diamino-2-methylpentane (Dytek A from. DuPont), 1, 6-diaminohexane, 2,5-diamino-2, 5-dimethylhexane, 2,2,4- and / or

2,4,4-trimethyl-l, 6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1-

Amino-3,3,5-trimethyl-5-aminomethylcyclohexane (IPDA), 1,3-diamino-2- and / or 4-methylcyclohexane, isopropyl-2,4- and / or 2,6-diaminocyclohexane, l, 3-bis (aminomethyl) cyclohexane, 2,4'- and / or 4,4'-diamino-dicyclohexylmethane, 3,3'-dimethyl-

4,4'-diamino-dicyclohexyl methane (Laromin C 260 ^®, BASF SE, Ludwigshafen, DE), the isomeric, a methyl group as ring substituent having Diaminodicyclohexyl- methane (C-monomethyl-diaminodicyclohexyl methanes), 3 (4) - aminomethyl 1 - methylcyclohexylamine and 1,3-bis (aminomethyl) benzene. _

Suitable tri- or higher-functional amines for the preparation of polyaspartic esters A) are those of the formula (II) in which n is an integer> 3, such. B. 4-aminomethyl-l, 8-octanediamine, 2,2 ', 2 "-triaminotriethylamine, 1,3,5-tris (aminomethyl) -2,4,6-triethylbenzene, tris-l, l, 1-aminoethylethane, 1,2,3-triamionopropane, tris (3-aminopropyl) amine and N, N, N ', N'-tetrakis (2-aminoethyl) ethylenediamine.

Suitable amines (II) for preparing the aspartic acid esters or polyaspartic esters A) are in principle also monoamines (n = 1) and diamines (n = 2) which contain further groups reactive toward isocyanates in the temperature range from 20 to 200 ° C., for example, amino alcohols, such as. For example, 2-aminoethanol, the isomeric Aminopropano- Ie and -butanols, 3-amino-l, 2-propanediol and 1,3-diamino-2-propanol.

Low molecular weight polyether polyamines with aliphatically bound primary amino nogruppen as they are (Huntsman Performance Products, The Woodlands, Texas, USA) for example, sold under the name Jeffamine ^®, provide in principle is suitable amino components for the production of polyaspartic esters A). Preferred amino component but are those of the formula (II) in which n is 2, in particular aliphatic and / or cycloaliphatic diamines of the abovementioned type. Very particularly preferred amino components for preparing the polyaspartic esters A) are l, 5-diamino-2-methylpentane, 2,4 '- and / or 4,4'-diamino-dicyclo-hexylmethane and / or 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane. Fumaric acid diesters or maleic diesters of the formula (III) are used in the preparation of the aspartic acid esters or polyaspartic esters A), in which the radicals R ¹ and R ^{2 represent} identical or different radicals and organic radicals having 1 to 18, preferably 1 to 9 , particularly preferably 1 to 4, mean carbon atoms.

Preference is given to using maleic acid esters of formula (III) in which the radicals R ¹ and R ^{2 represent} identical or different radicals and are a methyl, ethyl, n-butyl or 2-ethylhexyl radical. Very particularly preferred polyaspartic esters A) are those which have been prepared using diethyl maleate.

The preparation of aspartic acid esters or polyaspartic esters A) can be carried out both in solution and solvent-free. In both cases, an equimolar reaction of the amine (II) with the fumaric diester and / or maleic diester (III) is preferably carried out. For a specific variation of performance properties, the equivalence ratio of maleic acid ester and / or fumaric acid ester (III) to _ _

Amino groups of component (II) of 1, 2: 1 to 1: 2, are varied. If mixtures of aspartic acid esters or polyaspartic esters A) are used in the coating composition according to the invention, the preparation of the polyasparagric esters can be carried out separately or in a reaction vessel. In addition to the amines A), the coating compositions of the invention may optionally contain further components B) containing isocyanate-reactive groups.

These are, for example, compounds which contain at least two structural elements of the formula (IV)

/ -N = C ^ (IV)

exhibit. These compounds B), which are referred to in the context of the present invention as polyaldimines or polyketimines, generally have molecular weights of from 112 to 6500, preferably from 140 to 2500, particularly preferably from 140 to 458.

The preferred polyaldimines or polyketimines optionally used as component B) include compounds of the formula (V)

in which

R ³ and R ^{4 are the} same or different radicals and hydrogen or inert organic radicals, such as. B. hydrocarbon radicals having up to 8 carbon atoms, in particular alkyl radicals having 1 to 8 carbon atoms, and wherein the radicals R ³ and R ⁴ together with the carbon atom can form a 5- or 6-membered cycloaliphatic ring, with the proviso that the Radicals R ³ and R ^{4 are} not simultaneously hydrogen, and _ _

X has the meaning given above in the description of amines A) and

m stands for an integer> 2.

Particular preference is given to compounds of the formula (V) in which all radicals R ^{3 are} hydrogen, the radicals R are hydrocarbon radicals having up to 8 carbon atoms and m = 2.

The aldehydes or ketones which can be used for the preparation of the polyaldimines or polyketimines correspond to the formula (VI)

R ³

\ (VI) C = O

R ⁴

and preferably have a molecular weight of 58 to 198 (ketones) and 44 to 128 (aldehydes). Suitable aldehydes for the preparation of the polyaldimines optionally used as component B) are, for example, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, trimethylacetaldehyde, 2,2-dimethylpropanal, 2-ethylhexanal, 3-cyclohexane-1-carboxaldehyde, hexanal, Heptanal, octanal, valeraldehyde, benzaldehyde, tetrahydrobenzaldehyde, hexahydrobenzaldehyde, propargyl aldehyde, p-tolualdehyde, phenylethanal, 2-methylpentanal, 3-methylpentanal, 4-methylpentanal, sorbaldehyde.

Particular preference is given to n-butyraldehyde, isobutyraldehyde, trimethylacetaldehyde, 2-ethylhexanal and hexahydrobenzaldehyde.

Suitable ketones for the preparation of the polyketimines optionally used as component B) are, for example, acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl tert-butyl ketone, methyl n-amyl ketone, methyl isoamyl ketone, methyl heptyl ketone, methyl undecyl ketone, di ethyl ketone, ethyl butyl ketone, ethyl amyl ketone, diisopropyl ketone, diisobutyl ketone, cyclohexanone, cyclopentanone, methylcyclohexanone, isophorone, 5-methyl-3-heptanone, 1-phenyl-2-propanone, acetophenone, methyl nonyl ketone, dinonyl ketone, 3,3,5-trimethyl - cyclohexanone. - o -

Particularly preferred are cyclopentanone, cyclohexanone, methylcyclopentanone, methylcyclohexanone, 3,3,5-trimethylcyclopentanone, cyclobutanone, methylcyclobutanone, acetone, methyl ethyl ketone, methyl isobutyl ketone.

Of course, it is also possible to use any desired mixtures of different ketones or aldehydes and also mixtures of ketones with aldehydes in order to achieve special properties.

The polyamines used for the preparation of the polyaldimines or polyketimines used as component B) in the novel coating compositions are the amines of the general formula (II) already explicitly described above in connection with the preparation of the polyaspartic esters A). in which n is an integer> 2, or any mixtures of such polyamines. Preferred polyamine for the preparation of component B) is 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (IPDA). Very particular preference is given to the polyaldimine obtainable by the reaction of IPDA with isobutyraldehyde. The polyaldimines or polyketimines B) are prepared by methods known per se by reacting the starting components while maintaining a stoichiometric ratio of amino groups to aldehyde or keto groups of 1: 1 to 1: 1.5. Optionally, to accelerate the reaction catalytic amounts of acidic substances such. As p-toluenesulfonic acid, hydrochloric acid, sulfuric acid or aluminum chloride are used.

The reaction is generally carried out within the temperature range of 20 to 180 ° C, the reaction optionally using an entraining agent (eg., Toluene, xylene, cyclohexane and octane) to remove the water of reaction, carried out until the calculated amount in water (1 mole of water per mole of primary amino group) is split off or until no more water is split off. The phases are then separated or the entraining agent and, if present, unreacted starting materials are removed by distillation. The products thus obtained can be used without further purification as component B) in the coating compositions according to the invention. Further, likewise containing as isocyanate-reactive group-containing component B) for the coating compositions of the invention suitable compounds _ _

are the usual known from polyurethane chemistry polyhydroxyl compounds such. Example, polyester polyols, polyether polyols and / or polyacrylate polyols.

Suitable polyester polyols B) are, for example, those having a mean molecular weight, which can be calculated from functionality and hydroxyl number, of from 200 to 3000, preferably from 250 to 2500, having a hydroxyl group content of from 1 to 21% by weight, preferably from 2 to 18% by weight. %, as can be prepared in a manner known per se by reacting polyhydric alcohols with substancial amounts of polybasic carboxylic acids, corresponding carboxylic acid anhydrides, corresponding polycarboxylic acid esters of lower alcohols or lactones. For the preparation of these polyester polyols suitable polyhydric alcohols are especially those of the molecular weight range 62 to 400 such. 1,2-ethanediol, 1,2- and 1,3-propanediol, the isomeric butanediols, pentanediols, hexanediols, heptanediols and octanediols, 1,2- and 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 4, 4 '- (1-methylethylidene) biscyclohexanol, 1,2,3-propanetriol, 1,1,1-trimethylolethane, 1, 2,6-hexanetriol, 1,1,1-trimethylolpropane, 2,2-bis (hydroxymethyl) -1,3-propanediol or 1,3,5-tris (2-hydroxyethyl) isocyanurate.

The acids or acid derivatives used to prepare the polyester polyols B) may be aliphatic, cycloaliphatic and / or heteroaromatic in nature and optionally, for. B. by halogen atoms, substituted and / or unsaturated. Examples of suitable acids are, for example, polybasic carboxylic acids in the molecular weight range from 118 to 300 or derivatives thereof, for example succinic, adipic, sebacic, phthalic, isophthalic, trimellitic, phthalic, tetrahydrophthalic, maleic, maleic, dimeric and trimeric fatty acids, terephthalic bis-glykolester. To prepare the polyesterpolyols B) it is also possible to use any mixtures of these starting compounds exemplified.

Suitable polyester polyols B) are also those as they are in a conventional manner from lactones and simple polyhydric alcohols, such as. As the above exemplified, can be prepared as starter molecules under ring opening. Suitable lactones for the preparation of these polyester polyols are, for example, β-propiolactone, γ-butyrolactone, γ- and δ-valerolactone, ε-caprolactone, 3,5,5- and 3,3,5-trimethylcaprolactone or any desired mixtures of such lactones. - -

The preparation of these lactone is generally carried out in the presence of catalysts such as Lewis or Brönstedt acids, organic tin or titanium compounds at temperatures of 20 to 200 ° C, preferably 50 to 160 ° C.

Suitable polyether polyols B) are, for example, those having a mean molecular weight, which can be calculated from functionality and hydroxyl number, of 200 to 6000, preferably 250 to 4000, having a hydroxyl group content of 0.6 to 34% by weight, preferably 1 to 27% by weight. -%, as they are accessible in a conventional manner by alkoxylation of suitable starter molecules. For the preparation of these polyether polyols, any polyhydric alcohols, for example those of the molecular weight range 62 to 400, as described above in the preparation of polyester polyols, can be used as starter molecules.

Alkylene oxides which are suitable for the alkoxylation reaction are, in particular, ethylene oxide and propylene oxide, which can be used in any desired order or even as a mixture in the alkoxylation reaction. Suitable Polyacrylatpoylole B) are, for example, those of an average of functionality and hydroxyl number calculable molecular weight of 800 to 50,000, preferably from 1000 to 20,000, with a hydroxyl group content of 0.1 to 12% by weight, preferably 1 to 10, as in can be prepared by copolymerization of hydroxyl-containing olefinically unsaturated monomers with hydroxyl-free olefinic monomers.

Examples of suitable monomers for preparing the polyacrylate polyols B) are vinyl or vinylidene monomers such as styrene, α-methylstyrene, o- or p-chlorostyrene, o-, m- or p-methylstyrene, p-tert-butylstyrene, acrylic acid , Acrylonitrile, methacrylonitrile, acrylic and methacrylic acid esters of alcohols having up to 8 carbon atoms, such as. Ethyl acrylate, methyl acrylate, n- or isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate or isooctyl methacrylate, diesters of fumaric acid, itaconic acid or maleic acid having 4 to 8 carbon atoms having alcohols, acrylamide, methacrylic acid amide, vinyl esters of alkanemonocarboxylic acids having 2 to 5 carbon atoms, such as. As vinyl acetate or vinyl propionate, hydroxyalkyl esters of acrylic acid or methacrylic acid having 2 to 4 carbon atoms in the hydroxyalkyl radical, such as. For example, 2-hydroxyethyl, 2-hydroxypropyl, 4-hydroxybutyl, trimethylolpropane mono- or pentae - -

rythritol monoacrylate or methacrylate, as well as any mixtures of such exemplified monomers.

In the coating compositions according to the invention, the said isocyanate-reactive components B) may optionally also be used in the form of any desired mixtures.

In this case, components B) are present in an amount of up to 50% by weight, preferably up to 40% by weight, more preferably up to 30% by weight, based on the total amount of components A) and B). for use.

As crosslinker component C), the coating compositions according to the invention contain silane-containing polyisocyanate components.

These are, for example, the known reaction products of low-monomer aliphatic and / or cycloaliphatic lacquer polyisocyanates with molar amounts of isocyanate-reactive silane units relative to the content of isocyanate groups. Suitable silane-containing polyisocyanates C) are, for example, the reaction products of aliphatic or cycloaliphatic polyisocyanates, such as those described in WO 2003/054049, JP-A 2005 015644 and EP-A 1 273 640. B. polyisocyanurates of 1,6-diisocyanatohexane (HDI) or 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate, IP-DI), with secondary, N-alkyl-substituted aminoalkyltrialkoxysilanes or N, N-bis (3-trialkoxysilylpropyl) -amines or the reaction products of aliphatic or cycloaliphatic polyisocyanates claimed in EP-B 0 994 139 with substoichiometric amounts of alkoxysilane-functional aspartic acid esters, as described in EP-A 0 596 360 as reactants for isocyanate-functional compounds , Reaction products of aliphatic or cycloaliphatic polyisocyanates with substoichiometric quantities of alkoxysilane-functional aspartic acid esters or secondary aminoalkylsilanes suitable as crosslinker component C) are also already known from WO 02/058569.

In the coating compositions of the invention, however, the polyisocyanate component C) used is preferably allophanate polyisocyanates containing silane groups, which are prepared by reacting - -

c1) at least one hydroxyurethane and / or hydroxyamide having silane groups obtainable from the reaction of aminosilanes with cyclic carbonates or lactones with a molar excess of c2) of at least one diisocyanate with aliphatic, based on the NCO-reactive groups of component c1); cycloaliphatic, araliphatic and / or aromatically bonded isocyanate groups and optionally subsequent removal of unreacted Diisocyanatüber- shot were obtained. The preparation of such silane-containing allophanate polyisocyanates is not claimed in the context of the present invention. It is carried out by reacting silane-containing hydroxyurethanes or hydroxyamides which are accessible from aminoalkylsilanes with cyclic carbonates or lactones with ring opening, with excess amounts of monomeric diisocyanates, and is the subject of EP-A 2 014 692.

Starting compounds c1) for preparing the silane-containing polyisocyanate component C), particularly suitable allophanate polyisocyanates are any reaction products of aminosilanes with cyclic carbonates or lactones.

Suitable aminosilanes for preparing the starting compounds c1) are, for example, those of the general formula (VII)

R ⁵

R6-Si - Y N -H (VII)

R ⁷ R ⁸

in which

R ⁵ , R ⁶ and R ^{7 are the} same or different radicals and each represents a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic radical or an optionally substituted aromatic or araliphatic radical having up to 18 carbon atoms, optionally up to 3 heteroatoms from the series oxygen, sulfur, nitrogen may contain, - -

is a linear or branched organic radical having at least 2 carbon atoms, which may optionally contain up to 2 imino (- NH-), and R is hydrogen, a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or an optionally substituted aromatic or Araliphatic radical having up to 18 carbon atoms or a radical of the formula

R ⁵

IR ⁶ - Si - Y

R ⁷

in which R ⁵ , R ⁶ , R ⁷ and Y have the meaning given above.

Suitable aminosilanes are, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylethyldiethoxysilane, 3-aminopropyldimethylethoxysilane, 3-aminopropyldiisopropylethoxysilane, 3-aminopropyltripropoxysilane, 3-aminopropyltri butoxysilane, 3-aminopropylphenyldiethoxysilane, 3-aminopropylphenyldimethoxysilane, 3-aminopropyltris (methoxyethoxyethoxy) silane, 2-aminoisopropyltrimethoxysilane, 4-aminobutyltrimethoxysilane, 4-aminobutyltriethoxysilane, 4-aminobutylmethyldimethoxysilane, 4-aminobutylmethyldiethoxysilane, 4-aminobutylethyldimethoxysilane, 4-aminobutylethyldiethoxysilane, 4-aminobutyldimethylmethoxysilane, 4-aminobutyl phenyldimethoxysilane, 4-aminobutylphenyldiethoxysilane, 4-amino (3-methylbutyl) methyldimethoxysilane, 4-amino (3-methylbutyl) methyldiethoxysilane, 4-amino (3-methylbutyl) trimethoxysilane, 3-aminopropylphenylmethyl-n-propoxysilane, 3-aminopro pylmethyldibutoxysilane, 3-Am inopropyldiethylmethylsilane, 3-aminopropylmethylbis (trimethylsiloxy) silane, 11-aminoundecyltrimethoxysilane, N-methyl-3-aminopropyltriethoxysilane, N- (n-butyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane , N- (2-aminoethyl) -3-aminoisobutylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltris (2-ethylhexoxy) silane, N- (6- Aminohexyl) -3-aminopropyltrimethoxysilane, N-benzyl N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, bis (3-trimethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl) amine, (aminoethylaminomethyl) phenethyltrimethoxysilane, N-vinylbenzyl-N- (2-aminoethyl) -3-aminopropylpolysiloxane, N-vinylbenzyl-N (2-aminoethyl) -3-aminopro-pylpolysiloxane, 3-ureidopropyltriethoxysilane, 3- (m-aminophenoxy) -propyltrimethoxysilane, m- and / or p-aminophenyltrimethoxysilane, 3- (3-aminopropoxy) - 3,3-dimethyl-1-propenyltrimethoxysilane, 3-aminopropylmethylbis (trimethylsiloxy) silane, 3-aminopropyltris (trimethylsiloxy) silane, 3-aminopropylpentamethyldisiloxane or any mixture of such aminosilanes.

Preferred aminosilanes for preparing the starting component cl) are those of the general formula (VII) in which

R ⁵ , R ⁶ and R ^{7 are} identical or different radicals and each represents a saturated, linear or branched, aliphatic or cycloaliphatic radical having up to 6 carbon atoms, which may optionally contain up to 3 oxygen atoms, Y is a linear or branched alkylene radical with 2 to 10 carbon atoms, which may optionally contain up to 2 imino groups (-NH-), and

R ^{8 represents} hydrogen, a saturated, linear or branched, aliphatic or cycloaliphatic radical having up to 6 carbon atoms or a radical of the formula

R ⁵ R6_ Si Y

R ⁷

in which R ⁵ , R ⁶ , R ⁷ and Y have the meaning given above. Particularly preferred aminosilanes for preparing the starting component c1) are those of the general formula (VII) in which

R ⁵ , R ⁶ and R ⁷ each represent alkyl radicals having up to 6 carbon atoms and / or alkoxy radicals which contain up to 3 oxygen atoms, with the dimensional would be that at least one of the radicals R ⁵ , R ⁶ and R ^{7 is} such an alkoxy radical,

Y is a linear or branched alkylene radical having 3 or 4 carbon atoms, and R ^{8 is} hydrogen, a methyl radical or a radical of the formula

R ⁵

IR ⁶ - Si - Y

R ⁷

in which R ⁵ , R ⁶ , R ⁷ and Y have the meaning given above.

Particularly preferred aminosilanes for preparing the starting component c1) are those of the general formula (VII) in which

R ⁵ , R ⁶ and R ^{7 are} each methyl, methoxy and / or ethoxy, with the proviso that at least one of R ⁵ , R ⁶ and R ^{7 is} a methoxy or ethoxy radical,

Y is a propylene radical (-CH ₂ -CH ₂ -CH ₂ -), and R ^{8 is} hydrogen, a methyl radical or a radical of the formula

R ⁵

IR ⁶ - Si - Y

R ⁷

in which R ⁵ , R ⁶ , R ⁷ and Y have the meaning given above.

Very particularly preferred aminosilanes are aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane and / or 3-aminopropylmethyldiethoxysilane.

In the preparation of the starting compounds c1) for the process according to the invention, the abovementioned aminosilanes are reacted with any cyclic carbonates and / or lactones with ring opening. - -

Suitable cyclic carbonates are in particular those having 3 or 4 carbon atoms in the ring, which may optionally also be substituted, such as. B. l, 3-dioxolan-2-one (ethylene carbonate, EC), 4-chloro-l, 3-dioxolan-2-one, 4,5-dichloro-l, 3-dioxolan-2-one, 4-methyl -l, 3-dioxolan-2-one (propylene carbonate, PC), 4-ethyl-1,3-dioxolan-2-one, 4,5-dimethyl-1,3-dioxolan-2-one, 4,4- Dimethyl-1,3-dioxolan-2-one, 4-hydroxymethyl-1,3-dioxolan-2-one (glycerol carbonate), 4-phenoxymethyl-1,3-dioxolan-2-one, 1,3-dioxane-2 - on (trimethylene carbonate), 5,5-dimethyl-1,3-dioxan-2-one, 5-methyl-5-propyl-l, 3-dioxan-2-one, 5-ethyl-5- (hydroxymethyl ) -l, 3-dioxan-2-one (TMP carbonate), 4-isopropyl-5,5-dimethyl-1,3-dioxan-2-one (2,2,4-trimethyl-pentane-l, 3 -diol carbonate), 4-tert-butyl-5-methyl-1,3-dioxan-2-one (2,4,4-trimethyl-pentane-1,3-diol carbonate), 2,4-dioxaspiro [5.5] - undecan-3-one (cyclohexane-1-dimethanol spiro-carbonate) or any mixtures of such cyclic carbonates. Preferred cyclic carbonates are ethylene carbonate and / or propylene carbonate.

Suitable lactones are, for example, those having 3 to 6 carbon atoms in the ring, which may optionally also be substituted, such as. B. β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, γ-valerolactone, γ-phenyl-γ-butyrolactone, α, α-diphenyl-γ-butyrolactone, γ-hexalactone (γ- Caprolactone), γ-hepta- lactone, γ-octalactone, γ-nonalactone, γ-decalactone, γ-undecalactone, γ-dodecalactone, γ-methyl-γ-decanolactone, α-acetyl-γ-butyrolactone, δ-valerolactone, δ Hexanolactone, δ-octanolactone, δ-nonanolactone, δ-decalactone, δ-undecalactone, δ-tridecalactone, δ-tetra-decalactone, γ-ethyl-γ-butyl-δ-valerolactone, octahydrocoumarin, ε-caprolactone, γ - Phenyl-ε-caprolactone, ε-decalactone or any mixtures of such lactones. Preferred lactones are β-propiolactone, γ-butyrolactone, γ-valerolactone, γ-caprolactone and / or ε-caprolactone. The preparation of the starting compounds c1) by reacting the abovementioned amino silanes with the cyclic carbonates or lactones is known per se and can be carried out, for example, by the processes described in SU-A 295764, US Pat. No. 4,104,296, EP-A 0 833 830 or WO 1998 / 018844. In general, while the reactants are reacted at temperatures of 15 to 100 ⁰ C, preferably 20 to 60 ⁰ C in equimolar quantities to react together. But it is also possible that one of the components, for example the aminosilane or the cyclic carbonate or lactone, is used in a molar excess amount, but preferably in an excess of not more than 10 mol%, particularly preferably not more than 5 mol% , The way - -

available hydroxyflinktionellen starting compounds cl) containing urethane groups when using cyclic carbonates, amide groups when using lactones, are generally colorless low-viscosity liquids.

Suitable starting compounds c2) for the process according to the invention are any diisocyanates having aliphatically, cycloaliphatically, araliphatically and / or aromatically bound isocyanate groups which can be prepared by any desired method, for example by using B. by phosgenation or phosgene-free way, for example by urethane cleavage can be produced. Suitable starting diisocyanates are for example those of the molecular weight range 140 to 400 g / mol, such as. B. 1, 4-diisocyanatobutane, 1,6-diisocyanatohexane (HDI), l, 5-diisocyanato-2,2-dimethylpentane, 2,2,4- and 2,4,4-trimethyl-l, 6th diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- and 1,4-diisocyanato-cyclohexane, 1,1-diisocyanato-S, S-trimethylcyclohexane, 1,3-diisocyanato-2-methylcyclohexane, 1,3-diisocyanato 4-methylcyclohexane, 1-isocyanato-S ^ .S-trimethyl-S-isocyanatomethylcyclohexane (isophorone diisocyanate; IPDI), 1-isocyanato-1-methyl-4 (3) -isocyanatocyclohexane, 2,4'- and 4'-methylcyclohexane 4,4'-diisocyanatodicyclohexylmethane, 1,3- and 1,4-bis (isocyanatomethyl) cyclohexane, 4,4'-diisocyanato-3,3'-dimethyldicyclohexylmethane, 4,4'-diisocyanato-3,3 ', 5,5'-tetramethyldicyclohexylmethane, 4,4'-diisocyanato-1, 1'-bi (cyclohexyl), 4,4'-diisocyanato-3,3'-dimethyl-1,1 '-bi (cyclohexyl), 4, 4'-diisocyanato-2,2 ', 5,5'-tetra-methyl-1,1'-bi (cyclohexyl), 1,8-diisocyanato-p-menthane, 1,3-diisocyanato-adamantane , 1,3-dimethyl-5,7-diisocyanatoadamantane, 1,3- and 1,4-bis- (isocyanatomethyl) benzene, 1,3- and 1,4-bis (1-isocyanato-1-methylethyl) benzene (TMXDI), bis (4- (1-isocyanato-1-methylethyl) phenyl) carbonate, 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-toluene diisocyanate and any mixtures of these isomers, diphenylmethane-2,4'- and / or -4,4'-diisocyanate and naphthylene-l, 5-diisocyanate and any mixtures of such diisocyanates. Further likewise suitable diisocyanates can be found, for example, in Justus Liebigs Annalen der Chemie, Volume 562 (1949), pp. 75-136.

Preferred starting components c2) are the diisocyanates mentioned with aliphatically and / or cycloaliphatically bonded isocyanate groups. Particularly preferred starting components c2) for the process according to the invention are 1, 6-diisocyanatohexane, 1-isocyanato-S ^^ - trimethyl-S-isocyanatomethylcyclo-hexane, 2,4'- and / or 4,4'-diisocyanatodicyclohexylmethane or any mixtures thereof diisocyanates. - o -

To prepare the allophanate polyisocyanates which are particularly suitable as silane-containing polyisocyanate component C), the hydroxyurethanes and / or hydroxyamides cl) containing silane groups are reacted with the diisocyanates c2) at from 40 to 200 ° C., preferably from 60 to 180 ° C., while maintaining an equivalent Ratio of isocyanate groups to isocyanate-reactive groups of from 4: 1 to 50: 1, preferably from 5: 1 to 30: 1, converted to allophanate polyisocyanates.

In the case of the use of hydroxyurethanes, the urethane groups already present herein include "urea groups reactive in addition to isocyanate groups" in addition to the hydroxyl groups of component cl) and the urethane groups intermediately formed therefrom by NCO / OH reaction, since these are also present under the reaction conditions react to allophanate groups.

The preparation of the allophanate polyisocyanates containing silane groups can be carried out uncalcalyzed as thermally induced allophanatization. However, suitable catalysts are preferably used to accelerate the allophanatization reaction. These are the customary known allophanatization catalysts, for example metal carboxylates, metal chelates or tertiary amines of the type described in GB-A 0 994 890, alkylating agents of the type described in US Pat. No. 3,769,318 or strong acids, as described by way of example in EP-A-0 000 194.

Suitable allophanatization catalysts are, in particular, zinc compounds, such as, for example, zinc (II) stearate, zinc (II) n-octanoate, zinc (II) 2-ethyl-1-hexanoate, zinc (II) naphthenate or zinc (II) acetylacetonate, tin compounds, such as. Tin (II) n-octanoate, tin (II) 2-ethyl-l-hexanoate, tin (II) laurate, dibutyltin oxide, dibutyltin di- chloride, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dimaleate or dioctyltin diacetate, zirconium compounds, such as. Zirconium (IV) -2-ethyl-l-hexanoate, zirconium (rV) neodecanoate, zirconium (IV) naphthenate or zirconium (IV) acetylacetonate, aluminum tri (ethylaceto-) acetate), iron (III) chloride, potassium octoate, manganese cobalt or nickel compounds and strong acids, such as. As trifluoroacetic acid, sulfuric acid, hydrogen chloride, hydrogen bromide, phosphoric acid or perchloric acid, or any mixtures of these catalysts. - -

Suitable, albeit less preferred, catalysts for preparing the alanphanate polyisocyanates containing silane groups which are particularly suitable as the polyisocyanate component C) are also those compounds which, in addition to the allophanatization reaction, also catalyze the trimerization of isocyanate groups to form isocyanurate structures. Such catalysts are described, for example, in EP-A 0 649 866 page 4, line 7 to page 5, line 15.

Preferred catalysts are zinc and / or zirconium compounds of the abovementioned type. Very particular preference is given to using zinc (II) n-octanoate, zinc (II) 2-ethyl-1-hexanoate and / or zinc (II) stearate, zirconium (IV) n-octanoate, zirconium (IV) 2-ethyl-l-hexanoate and / or zirconium (IV) neodecanoate.

These catalysts are used in the preparation of the polyisocyanate component C) particularly suitable silane-containing AUophanatpolyisocyanate, if any, in an amount of 0.001 to 5 wt .-%, preferably 0.005 to 1 wt .-%, based on the total weight of the reactants cl) and c2) and can be added to the reaction both before the beginning of the reaction and at any time.

The preparation of the silane-containing AUophanatpolyisocyanate is preferably carried out solvent-free. Optionally, however, suitable solvents which are inert to the reactive groups of the starting components can also be used. Suitable solvents are, for example, the known conventional lacquer solvents, such as. Ethyl acetate, butyl acetate, ethylene glycol monomethyl or ethyl ether acetate, 1-methoxypropyl 2-acetate, 3-methoxy-n-butyl acetate, acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone, toluene, xylene, chlorobenzene, White spirit, higher substituted aromatics, as are for example under the names Solventnaphtha, Solvesso ^® , Isopar ^® , Nappar ^® (German EXXON CHEMICAL GmbH, Cologne, DE) and Shellsol ^® (Deutsche Shell Chemie GmbH, Eschborn, DE) commercially, but also solvents such as propylene glycol diacetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl and butyl ether acetate, N-methylpyrrolidone and N-methylcaprolactam, or any mixtures of such solvents. In one possible embodiment of the process for the preparation of the silane-group-containing isophanate polyisocyanates C), the starting diisocyanate c2) or a mixture of different starting diisocyanates, if appropriate under an inert gas, such as _ _

For example, nitrogen, and optionally in the presence of a suitable solvent of the type mentioned at a temperature between 20 and 100 ° C submitted. Subsequently, the hydroxy-functional starting compound cl) is added in the amount indicated above and, if appropriate, the reaction temperature for the urethanization by a suitable measure (heating or cooling) to a temperature of 30 to 120 ° C, preferably set from 50 to 100 ° C. Following the urethanization reaction, ie when the NCO content theoretically corresponding to a complete conversion of isocyanate and hydroxyl groups is reached, the allophanatization can be carried out, for example, without addition of a catalyst by heating the reaction mixture to a temperature of from 140 to 200 ° C are started. Preferably, however, useful catalysts of the above kind are for accelerating the allophanatization reaction was used, and depending on the type and amount of catalyst used, temperatures in the range of 60 to 140 ⁰ C, preferably 80 to 120 ° C, are sufficient. In another possible embodiment of the process for preparing the aldehyde-containing polyisocyanates C), the catalyst which may be used is admixed either with the silane component c1) and / or with the diisocyanate component c2) before the actual reaction is initiated. In this case, the intermediately forming and, when using hydroxyurethanes c1) in these urethane groups already present, spontaneously react further to the desired allophanate structure. In this type of single-stage reaction, the catalyst optionally containing starting diisocyanates c2) optionally under inert gas, such as nitrogen, and optionally in the presence of a suitable solvent of the type mentioned, usually at optimal for the allophanatization temperatures in the range of 60 to 140 ° C, preferably 80 to 120 ° C, and reacted with the optionally containing the catalyst silane component cl).

However, it is also possible to add the catalyst to the reaction mixture at any time during the urethanization reaction. In this execution of the inventive method is used for the running prior to catalyst addition pure urethanization reaction is usually a temperature in the range of 30 to 120 ⁰ C, preferably from 50 to 100 ⁰ C. After adding a suitable Catalyst, the Allophanatisierungreaktion finally at temperatures of 60 to 140 ° C, preferably from 80 to 12O ⁰ C performed.

The course of the reaction of cl) with c2) can be replaced by z. B. titrimetric determination of the NCO content be followed. After reaching the desired NCO content, preferably when the Allophanatisierungsgrad (ie calculated from the NCO content percentage of allophanate to allophanate, from the hydroxyl groups of the component cl) intermediately forming and when using hydroxyurethanes cl) in these already contained urethane groups ) of the reaction mixture is at least 80%, particularly preferably at least 90%, very particularly preferably after complete allophanatization, the reaction is stopped. This can be done by cooling the reaction mixture to room temperature in purely thermal reaction, for example. However, in the preferred concomitant use of an allophanatization catalyst of the type mentioned, the reaction is generally stopped by addition of suitable catalyst poisons, for example acid chlorides such as benzoyl chloride or isophthaloyl dichloride.

Preferably, the reaction mixture is then by thin film distillation under reduced pressure, for example at a pressure of less than 10 mbar, preferably below 3 mbar, more preferably below 1 mbar, under as gentle conditions as possible, for example at a temperature of 100 to 200 ° C, preferably from 120 up to 180 ° C, of volatiles (excess monomeric Diisocyana- th, optionally in the preparation of the starting compounds A) used in excess cyclic carbonates or lactones, optionally with solvents used and, in the absence of the use of a catalyst poison, optionally active catalyst). The resulting distillates, which in addition to the unreacted monomeric starting diisocyanates c2), optionally excessively used cyclic carbonates or lactones c2) and optionally used solvents and waiving the use of a catalyst poison optionally active catalyst, can be used without problems for re-oligomerization. In a further embodiment of the process for preparing the silane-containing allophanate polyisocyanates C), the volatile constituents mentioned are obtained by extraction with suitable isocyanate-inert solvents, - -

For example, aliphatic or cycloaliphatic hydrocarbons such as pentane, hexane, heptane, cyclopentane or cyclohexane separated from the oligomerization.

Regardless of the nature of the work-up, the polyisocyanate component C) which is obtained is particularly suitable silane-containing allophanate polyisocyanates in the form of clear, virtually colorless resins, which as a rule have color numbers of less than 200 APHA, preferably less than 100 APHA, more preferably less than 100 below 80 APHA, an average NCO functionality of 2.0 to 5.0, preferably 2.4 to 4.8, more preferably 3.0 to 4.5, and an NCO content of 6.0 to 20.5 Wt .-%, preferably 10.0 to 18.0 wt .-%, particularly preferably 12.0 to 17.0 wt .-%, have. When using selective allophanatization catalysts, they are virtually free of by-products such. B. isocyanurates, d. H. that in addition to isocyanate functions, at least one silane group is present in almost every molecule.

The coating compositions of the invention may optionally contain organic solvents D) and / or further auxiliaries and additives E).

Suitable solvents D) are, for example, the abovementioned conventional inert lacquer solvents which are optionally used in the preparation of the alanphanate polyisocyanates containing silane groups which are particularly suitable as polyisocyanate component C). If appropriate, such coating solvents are used in the coating compositions according to the invention in an amount of up to 50%, preferably up to 30%, particularly preferably up to 10%, based on the total amount of components A) to E).

As auxiliaries and additives E), for example, curing catalysts, fillers, dyes, pigments, matting agents, flame retardants, hydrolysis stabilizers, microbicides, algicides, flow control agents, antioxidants, light stabilizers, water scavengers, thixotropic agents, wetting agents or deaerating agents can be used. These auxiliaries and additives E) are mixed into the components A), B) and / or C) depending on the requirements of the problems to be solved by the application of the coating and their compatibility. Hydrous or strongly alkaline reacting additives should, for example, not the polyisocyanate component C) but the amine A) and / or optionally component B) are admixed. _ _

Suitable curing catalysts E) for the coating compositions according to the invention are, for example, the compounds known from polyurethane chemistry for accelerating isocyanate reactions, such as. B. the known tin or bismuth compounds and tertiary amines, as described for example in "Plastics Handbook 7, polyurethanes" Carl Hanser Verlag, Munich - Vienna, 1984, pp 97-98, in more detail. Such catalysts may be used, if at all, in amounts of up to 2% by weight, based on the weight of the binder consisting of the individual components A), optionally B) and C).

Suitable fillers are, for example, stone or plastic granules, glass beads, sand or cork, which can optionally be used in amounts of up to 100% by weight, based on the binder mixture consisting of the individual components A), optionally B) and C).

Examples of suitable pigments are titanium dioxide, zinc oxide, iron oxides, chromium oxides or carbon blacks. A detailed overview of pigments for paints are the "textbook of paints and coatings, Volume II, pigments, fillers, dyes", Kittel, Verlag WA Colomb in Heenemann GmbH, Berlin-Oberschwandorf, 1974, p 17-265. The pigments mentioned by way of example may be used, if at all, in amounts of up to 100% by weight, based on the binder mixture consisting of the individual components A), if appropriate B) and C). Matting agents, flame retardants, hydrolysis stabilizers, microbicides, algicides, leveling agents, antioxidants, light stabilizers, water scavengers, thixotropic agents, wetting agents or deaerating agents are also useful in the novel coating compositions as auxiliary agents and additives E), for example in "Lehrbuch der Lacke und Beschichtungen, Band III. , Solvents, Plasticizers, Additives, Intermediates ", H. Kittel, Verlag WA Colomb in Heenemann GmbH, Berlin-Oberschwandorf, 1976, pp. 237-398. Desiccants acting as water scavengers are described in more detail, for example, in "Kunststoff Handbuch 7, Polyurethane", Carl-Hanser-Verlag, Munich-Vienna, 1983, p. The total amount of such other auxiliaries and additives is generally up to 25 wt .-%, based on the consisting of the individual components A), optionally B) and C) binder. - -

The novel coating compositions are prepared by mixing the individual components A), C) and optionally B), D) and E), for example using the known dissolvers or vacuum dissolvers, which are often preferred in order to achieve extensive degassing of the coating compositions. When using components B) containing isocyanate-reactive groups, it is generally useful to prepare them in a first step with the polyamines A) and, if appropriate, further solvents D) and, if appropriate, further auxiliaries and additives E) to give a storage-stable binder component and the polyisocyanate component C), which may also optionally contain solvent D) and optionally further auxiliaries and additives E), as is customary in two-component systems, to add immediately before application. In this case, the quantitative ratio of the components A), optionally B) and C) is selected so that each isocyanate-reactive group of the components A) and optionally B) 0.7 to 2.0, preferably 0.8 to 1.6, particularly preferably 0.9 to 1.4 isocyanate groups of component C) are omitted.

The novel coating compositions can be prepared by conventional methods, for example by spraying, brushing, dipping, flooding or by means of rollers or squeegees on any substrates, such as. As metals, plastics, wood or glass, one or more layers apply. The lower proportion of required, if necessary, to be used organic solvent D) allows it to apply thick layers bubble-free in one operation.

The coating compositions according to the invention cure even at low temperatures, for example within the temperature range from -20 to + 60 ° C., preferably from -10 to + 40 ° C., to give light-stable and weather-resistant coating films which are characterized by high hardness and abrasion resistance combined with high Distinguish elasticity. However, if necessary, they can of course also be baked at relatively high temperatures, for example up to 14O ⁰ C.

The coating compositions according to the invention are particularly suitable for the production of coatings, in particular as anticorrosive coatings, on metallic materials such as are used, for example, in the production of vehicle bodies, machines, lining panels, drums or containers. - -

The substrates to be coated can be provided with suitable primers before the application of the inventive coating compositions. Due to their excellent direct adhesion to critical for conventional polyaspartic acid metallic substrates such. As zinc, aluminum or cold-rolled steel, can be dispensed with loss of quality but also on the co-use of a primer layer when using the inventive coating. In combination with the high layer thickness which can be applied in one operation, this means for the user of the coating composition according to the invention a significant reduction of the coating times and thus a noticeable increase in productivity. The present invention therefore also relates to the use of the novel coating compositions for coating substrates, in particular the use for the direct coating of metallic substrates and the use of the coating compositions as corrosion protection coating. Consequently, therefore, the films obtained from the coating compositions according to the invention and substrates coated therewith are also the subject of the present invention.

- zo -

Examples

All percentages are by weight unless otherwise stated.

The NCO contents were determined in accordance with DIN EN ISO 11909. All viscosity measurements were carried out using a Physica MCR 51 rheometer manufactured by Anton Paar Germany GmbH (Ostfüdern) in accordance with DIN EN ISO 3219.

The Hazen color numbers were determined on a LICO 400 colorimeter from Hach Lange GmbH, Dusseldorf.

The OH numbers given in the case of the starting compounds c1) were calculated from the theoretically resulting molecular weight of the ideal structure (1: 1 adduct).

starting compounds

Amine al)

Polyaspartic esters prepared in accordance with EP-B 0403921 (polyaspartic D)) by reaction of 2 mol of diethyl maleate with 1 mole of 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane (Laromin C 260 ^® Fa. BASF).

Viscosity: approx. 10000 mPas Equivalent weight: 290 g / val

Amine A2)

Polyaspartic acid ester prepared according to EP-B 0 403 921 (polyaspartic ester I)) by reacting 2 mol of diethyl maleate with 1 mol of 4,4'-diaminodicyclohexylmethane.

Viscosity: approx. 10000 mPas

Equivalent weight: 276 g / val Polyaldimine B)

Polyaldimine, prepared according to DE-A 2 325 824 by reacting 3 mol of isobutyric aldehyde with 1 mol of 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (IPDA) and subsequent work-up by distillation of the reaction mixture. Viscosity: approx. 30 mPas

Equivalent weight: 139 g / val

Preparation of the Starting Compounds C) Hydroxyurethane containing silane groups c1) 221 g (1.0 mol) of 3-aminopropyltriethoxysilane were initially introduced at room temperature under dry nitrogen. To this was added with stirring within 15 min 88 g (1.0 mol) of ethylene carbonate, the mixture due to the heat of reaction initially heated up to 34 ° C, and then stirred without further heating for 18 hours at room temperature. An amine titration with IN HCl showed a conversion of 99.8%.

2-Hydroxyethyl [3- (triethoxysilyl) propyl] urethane was obtained as a colorless liquid. Viscosity (23 ° C): 69 mPas

OH number (calculated): 181 mg KOH / g

Molecular weight (calculated): 309 g / mol

Silane-containing polyisocyanate component C)

1680 g (10.0 mol) of hexamethylene diisocyanate (HDI) were added at a temperature of 80 ° C under dry nitrogen with 309 g (1.0 mol) of the silane-containing hydroxyurethane cl) and stirred for 3 hours until an NCO content of 40.1%, corresponding to a complete urethanization. Subsequently, the reaction mixture was heated to 95 ° C and 0.5 g of zinc (II) -2-ethyl-l-hexanoate added as lophanatisierungskatalysator. Due to the exothermic reaction, the temperature of the mixture rose up to 110 ° C. After about 30 minutes, the NCO content of the reaction mixture was 35.9%. The catalyst was added by addition of 1 g - -

Deactivates benzoyl chloride and the unreacted monomeric HDI separated at a temperature of 130 ° C and a pressure of 0.1 mbar in a thin-film evaporator. This gave 789 g of a virtually colorless, clear allophanate polyisocyanate having the following characteristics: NCO content: 13.7% monomeric HDI: 0.03%

Viscosity (23 ° C): 1270 mPas

Color Number (APHA): 21 Hazen

NCO functionality:> 3 (calculated) Silane group content: 9.6% (calculated as SiO ₃ , molar mass = 76 g / mol)

Silane group-free comparison polvovocvanate V)

Isocyanurate group-containing HDI polyisocyanate, prepared on the basis of Example 11 of EP-A 0 330 966, with the modification that 2-ethylhexanol instead of 2-ethyl-1,3-hexanediol was used as the catalyst solvent.

NCO content: 23.0%

NCO functionality: 3.2

Monomeric HDI: 0.1%

Viscosity (23 ° C): 1,200 mPas

Example 1 and 2 (according to the invention and comparison)

From the raw materials listed in Table 1 below, an amino-functional binder component was prepared by predischarging for 10 minutes with the aid of a dissolver and subsequent grinding on a bead mill with cooling in the proportions indicated there. - -

Table 1 :

Molecular Sieve, UOP GmbH, D-51368 Leverkusen, Germany

²⁾ Dispersing additives / deaerating agents, Byk-Chemie GmbH, 46483 Wesel, Germany

³⁾ Pigment, Tronox Pigments GmbH, 42789 Krefeld, Germany

⁴⁾ Pigment, Lanxess, 51369 Leverkusen, Germany

⁵⁾ Pigment, Heubach GmbH & Co. KG, 38685 Langeisheim, Germany

⁶⁾ Filler, Sachtleben Chemie GmbH, D-47198 Duisburg, Germany

⁷⁾ Rheology Additive, Cabot GmbH, 63457 Hanau, Germany 8 ^ Light stabilizer, Ciba, Basel, Switzerland

To prepare a ready-to-use coating agent according to the invention, 45.46 parts by weight of the polyisocyanate component C) containing silane groups, corresponding to an equivalent ratio of isocyanate groups to isocyanate-reactive groups of 1.1: 1, were added to this binder component and incorporated well. - -

For comparison, 27.08 parts by weight of the silane-group-free comparative polyisocyanate V), likewise corresponding to an equivalent ratio of isocyanate groups to isocyanate-reactive groups of 1.1: 1, were added in a second coating batch of the same binder component and likewise well incorporated , The two formulations thus formulated, which had comparable pot lives of about 2 hours, were applied to a degreased aluminum sheet and to cold-rolled steel with the aid of an airless spray system, each in a wet film thickness of about 120 μm, and at room temperature (approx. 23 ° C) and a relative humidity of about 50%. The drying times according to DIN 53 150 were also comparable with Tl about 50 minutes and T6 about 2 hours.

Significant differences were found in the adhesion properties of the two coatings. As shown in Table 2 results of the cross-hatch tests according to ISO 2409, has the inventive silane-containing polyisocyanate cross-linked coating both on aluminum and cold rolled steel compared to a conventional, d. H. with a silane-free polyisocyanate crosslinked system significantly improved adhesion.

Table 2: Cross-cut tests according to DIN EN ISO 2409

- -

Examples 3 and 4 (according to the invention and comparison)

From the raw materials listed in Table 3 below, an amino-functional binder component was prepared by predischarging for 10 minutes with the aid of a dissolver and subsequent grinding on a bead mill with cooling in the proportions indicated there.

Table 3:

^1} Molecular Sieve, UOP GmbH, D-51368 Leverkusen, Germany 2 ⁾ Suspending Agent, Elementis Specialties, 9000 Gent / Belgium

³⁾ Dispersing additives / deaerating agents, Byk-Chemie GmbH, 46483 Wesel, Germany

⁴⁾ Pigment, Lanxess, 51369 Leverkusen, Germany

⁵⁾ Pigment, Tronox Pigments GmbH, 42789 Krefeld, Germany

⁶⁾ Filler, Sachtleben Chemie GmbH, D-47198 Duisburg, Germany 7 ⁾ Rheology Additive, Cabot GmbH, 63457 Hanau, Germany

⁸⁾ Sunscreens, Ciba, Basel, Switzerland - -

37.66 parts by weight of the silane group-containing polyisocyanate component C), corresponding to an equivalent ratio of isocyanate groups to isocyanate-reactive groups of 1.1: 1, were added to this binder component and incorporated well into this binder component.

For comparison, 22.43 parts by weight of the silane-free comparative polyisocyanate V), likewise corresponding to an equivalent ratio of isocyanate groups to isocyanate-reactive groups of 1.1: 1, were added in a second coating batch of the same binder component and likewise incorporated well. The two paints formulated in this way were applied to a degreased aluminum sheet and to cold-rolled steel with the aid of an airless spray coating in a wet film thickness of about 120 μm and at room temperature (about 23 ° C.) and a relative atmospheric humidity of approx. 50% cured. The drying times according to DEN 53 150 were comparable with Tl about 80 min and T6 about 4 hours. The pot lives of the coating compositions were about 6 hours in both cases.

As in Examples 1 and 2, clear differences in the adhesion properties of the two coatings also showed here. Table 4 shows the results of cross hatch tests according to ISO 2409. Thereafter, the inventive, crosslinked with a silane-containing polyisocyanate coating has both aluminum and cold rolled steel compared to a conventional, d. H. with a silane group-free polyisocyanate crosslinked system improved adhesion.

Table 4: Cross-cut tests according to DIN EN ISO 2409

Claims

- Patent claims:

1. Coating composition containing

A) at least one amine of the formula (I)

in which X is an n-valent, isocyanate-inert radical, as obtained by removing the primary amino groups from an organic polyamine in the molecular weight range 60 to 6000 with n primary aliphatic and / or cycloaliphatic bound amino groups, optionally one or contains several heteroatoms and / or further isocyanate-reactive and / or inert at temperatures up to 100 ° C functional groups, R ¹ and R ^{2 are the} same or different organic radicals having 1 to 18

Carbon atoms and n is an integer> 1, B) optionally further isocyanate-reactive components,

C) a silane group-containing polyisocyanate component,

D) optionally organic solvents and

E) optionally further auxiliaries and additives, with the proviso that the components A), optionally B) and C) are present in such proportions that reacts to each isocyanate-reactive

Group of components A) and optionally B) 0.7 to 2.0 isocyanate groups of component C) are omitted.

2. Coating composition according to claim 1, characterized in that as the amine A) polyaspartic acid esters are used which are obtained by reaction of a primary amino-containing component of the formula (II)

^X + ^NH ₂ ] _n C ^O) - -

with fumaric acid esters and / or maleic acid esters of the formula (III)

R ¹ 0OC-CH = CH - COOR ² (III)

wwoobbeeii XX undnd nn iinn ^' . Formula (II) and R ¹ and R in formula (III) have the meaning given in claim 1.

3. Coating composition according to claim 2, characterized in that are used as the amine A) polyaspartic acid ester, by reaction of l, 5-diamino-2-methylpentane, 2,4'- and / or 4,4'-diamino-dicyclohexylmethane and or 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane were prepared with diethyl maleate.

4. Coating composition according to claim 1, characterized in that as isocyanate-reactive component B) polyaldimines and / or polyketimines of the formula (V)

be used, in which

R ³ and R ^{4 are the} same or different radicals and hydrogen or inert organic radicals, such as. B. hydrocarbon radicals having up to 8 carbon atoms, in particular alkyl radicals having 1 to 8 carbon atoms, and wherein the radicals R ³ and R ⁴ together with the carbon atom can form a 5- or 6-membered cycloaliphatic ring, with the proviso that the Radicals R ³ and R ^{4 are} not simultaneously hydrogen, and X has the meaning given in claim 1 and m is an integer> 2.

5. Coating composition according to claim 1, characterized in that as polyisocyanate component C) silane groups-containing allophanate polyisocyanates are used, which by reacting cl) at least one of the reaction of aminosilanes with cyclic carbonates or lactones available silane groups having hydroxyurethane and / or hydroxyamides having a molar excess of c2) relative to the NCO-reactive groups of component c1) at least one diisocyanate having aliphatically, cycloaliphatically, araliphatically and / or aromatically bound isocyanate groups and optionally subsequent removal of the unreacted diisocyanate excess were obtained.

6. Coating composition according to claim 5, characterized in that as component cl) reaction products of aminosilanes of the general formula (VII)

R ⁵

R ⁶ - Si - Y NH (VII)

R ⁷ R ⁸ in which

R ⁵ , R ⁶ and R ^{7 are} identical or different radicals and are each a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or an optionally substituted aromatic or araliphatic radical having up to 18 carbon atoms, optionally up to 3 heteroatoms the series may contain oxygen, sulfur, nitrogen,

Y is a linear or branched organic radical having at least 2 carbon atoms, which may optionally contain up to 2 I-minogruppen (-NH-), and

R ^{8 is} hydrogen, a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or an optionally substituted aromatic or araliphatic radical having up to 18 carbon atoms or a radical of the formula - J -

R ⁵

IR ⁶ - Si - Y-

R ⁷ , in which R ⁵ , R ² , R ⁷ and Y have the abovementioned meaning, are used with cyclic carbonates and / or lactones.

7. Use of the coating composition according to claim 1 for the coating of substrates.

8. Use of the coating composition according to claim 1 for the direct coating of metallic substrates.

9. Use of the coating composition according to claim 1 as corrosion protection varnish.

10. With coated films obtained from coating compositions according to claim 1 coated substrates.