POLYSILOXANE-FUNCTIONALIZED POLYURETHANES TO INCREASE THE HYDROPHOBIA OF SURFACES

Description

[0001] The present invention relates to an NCO-terminated polysiloxane prepolymer, a process for its preparation, a formulation containing the NCO-terminated polysiloxane prepolymer and the use of this NCO-terminated polysiloxane prepolymer in a paint formulation.

[0002] It is known that NCO-terminated prepolymers can be used as curing components in polyurethane paint or coating systems. These prepolymers are generally obtained by reacting polyols with di- or polyisocyanates. As a curing component, the prepolymers then react with other polyols, such as polyacrylate polyols, in the paint or coating system to form the corresponding polyurethanes. It is desirable for the surfaces of these coating materials to exhibit hydrophobic properties, for example, to minimize the adhesion of water and / or dirt.

[0003] It is already known from the state of the art to incorporate siloxane units into the coating materials in order to increase the hydrophobicity of the corresponding surface.

[0004] WO 2018 / 146016 A1 describes copolymers containing at least three structural units: a component containing at least one biuret or isocyanurate substructure, a polysiloxane as a further component, and a third component containing another hydrocarbon with at least six carbon atoms that is different from the second component. These copolymers are used to impart hydrophobic properties to textiles.

[0005] WO 2017 / 151621 A1 discloses non-isocyanate-functionalized, siloxane-modified glycidyl carbamates for use in coating materials. The glycidyl carbamates are obtained by reacting organic polyisocyanates, glycidol, and at least one bis(hydroxyalkyl)-terminated polydimethylsiloxane.

[0006] US 2008 / 0213599 A1 describes a polymeric material obtained by reacting a mixture containing amino-functional polyorganosiloxanes, polyisocyanates, and polyols. This material can be used as an antifouling coating.

[0007] US 2014 / 0275410 A1 discloses an isocyanate-terminated polysiloxane copolymer that can be used as a curing agent or co-reactant in coating materials. To prepare this copolymer, a methoxy-functionalized polysiloxane, such as methylphenyl polysiloxane, is reacted with a polyisocyanate to obtain the desired copolymer. In coating materials, this copolymer then reacts with isocyanate-reactive groups to form the corresponding polyurethanes.

[0008] WO 2014 / 149331 A1 also relates to an isocyanate-terminated polysiloxane that can be used as a curing agent in coating systems. To produce this polysiloxane, a methoxy-functionalized polysiloxane is also hydrolyzed and then reacted with a polyisocyanate.

[0009] US 2015 / 307745 A1 concerns moisture-curing coatings which are used as antifouling coatings and therefore have surface hydrophobicity.

[0010] In the systems known from the state of the art, the compatibility of the siloxane building blocks in the coating system can be partially improved. Another problem is the accumulation of siloxane chains on the surface of the coating. If the siloxane chains are largely present on the surface of the coating, contact with water and scratching of the surface can lead to the removal of the siloxane layer, thus losing the desired hydrophobicity of the surface provided by the siloxane chains. Therefore, the existing polysiloxane building blocks should have a sufficiently strong bond to the matrix. Furthermore, the strength of the surface hydrophobicity can be further increased.

[0011] The object of the present invention is therefore to produce a polysiloxane-based hardener for a polyurethane-based coating material that exhibits greater surface hydrophobicity than coatings known from the prior art. Furthermore, this hydrophobicity should not be affected by scratching the surface or the effects of water on the surface. A further object of the present invention is therefore to provide correspondingly suitable polysiloxane building blocks for use as hardeners in coating materials that exhibit particularly high compatibility and bonding with the matrix.

[0012] These objects are achieved according to the invention by the NCO-terminated polysiloxane prepolymer of the general formula (I) [(Q) q ]-[(M) m -(P) p -(R) r ] t (I), wherein R, P, M, Q, r, p, m, q and t have the following meanings R each independently of one another is at least one polyisocyanate unit and / or at least one diisocyanate unit, P each independently of one another is at least one polyol unit, M each independently of one another is at least one diisocyanate unit and / or at least one polyisocyanate unit, Q at least one polysiloxane unit, r each independently of one another is a number from 1 to 10, p each independently of one another is a number from 1 to 10, m each independently of one another is a number from 1 to 10, q each independently of one another is a number from 1 to 10, t an integer from 2 to 5, and the existing units M are directly connected to the unit Q.

[0013] The above objects are further achieved by a process for producing an NCO-terminated polysiloxane prepolymer according to the invention, comprising at least the following steps: (A) reacting at least one polysiloxane polyol with at least one diisocyanate and / or at least one polyisocyanate to obtain at least one NCO-terminated polysiloxane, (B) optionally removing excess at least one diisocyanate or at least one polyisocyanate, (C) reacting the at least one NCO-terminated polysiloxane from step (A) or (B) with at least one polyol, (D) reacting the product obtained in step (C) with at least one polyisocyanate or at least one diisocyanate to obtain the NCO-terminated polysiloxane prepolymer, and by the formulation according to the invention comprising at least one NCO-terminated polysiloxane prepolymer according to the invention, and by the use of the NCO-terminated polysiloxane prepolymer according to the invention as a hardener in a paint formulation.

[0014] The present invention will be described in detail below.

[0015] The present invention relates to the NCO-terminated polysiloxane prepolymer of the general formula (I) [(Q) q ]-[(M) m -(P) p -(R) r ]t (I), wherein R, P, M, Q, r, p, m, q and t have the meanings given above.

[0016] The prepolymer of general formula (I) according to the invention is NCO-terminated. In the context of the present invention, "NCO-terminated" means that preferably 2 to 24 wt.%, particularly preferably 4 to 15 wt.%, and most preferably 5 to 12 wt.%, of the terminal functional groups are isocyanate groups, i.e., NCO groups.

[0017] The prepolymer of the invention of general formula (I) can, in principle, have any molecular weight known to the person skilled in the art. In a preferred embodiment of the present invention, the number-weighted molecular weight Mn of the prepolymer of the invention is 445 to 8500 g / mol, particularly preferably 550 to 6000 g / mol, and most preferably 600 to 5500 g / mol.

[0018] In a preferred embodiment of the present invention, the degree of branching of the prepolymer according to the invention is 2 to 14, particularly preferably 3 to 12, most particularly preferably 4 to 10.

[0019] In the general formula (I), R, P, M, Q, r, p, m, q and t have in particular the following meanings.

[0020] In the general formula (I), M denotes, independently of one another, at least one diisocyanate unit and / or at least one polyisocyanate unit. According to the invention, the units M present in each case are directly bonded to the unit Q. According to the invention, it is possible for 2 to 5 diisocyanate and / or polyisocyanate units M, preferably 2, 3, 4 or 5 diisocyanate and / or polyisocyanate units M, to be bonded to the polysiloxane unit Q. In a very particularly preferred embodiment, two diisocyanate and / or polyisocyanate units M are bonded to the polysiloxane unit Q.

[0021] According to the invention, in the general formula (I), M particularly preferably denotes, independently of one another, at least one diisocyanate unit, ie, 2 to 5, preferably 2, 3, 4 or 5, very particularly preferably 2, diisocyanate units M are present on the polysiloxane unit Q. These may be the same or different according to the invention; preferably, the diisocyanate units M attached to the polysiloxane unit Q are the same.

[0022] In the context of the present invention, "unit" means that the structural unit present in the compound of general formula (I) is derived from the reactive compounds described below. For example, if a diisocyanate is reacted with a diol or polyol, a urethane group is formed from one isocyanate group and one hydroxyl group. The rest of the compounds used, for example, the six methylene groups of hexamethylene diisocyanate, remain unchanged. Accordingly, "unit" in the context of the present invention refers to both the parts of the compounds that are not involved in the reaction and the functional groups, for example, a urethane group, that are formed by the reaction. In the context of the present invention, the corresponding unit is always derived from the compounds used in the synthesis.

[0023] "Independently" in the context of the present invention means that, if the corresponding unit occurs multiple times in the general formula (I), the units are identical or different and are each selected from the group of possible units. It is also possible according to the invention for a mixture of compounds of the general formula (I) to be present, with different possible units being present in the individual molecules.

[0024] According to the invention, the at least one diisocyanate unit M is preferably derived from a diisocyanate. Diisocyanates used as unit M are preferably selected from the group consisting of organic aliphatic, cycloaliphatic, araliphatic, aromatic diisocyanates, and mixtures thereof. Aliphatic and / or cycloaliphatic diisocyanates are preferably used as unit M.

[0025] Particularly preferred according to the invention as unit M are diisocyanates selected from the group consisting of 1,4-butane diisocyanate, 1,5-pentane diisocyanate (pentamethylene diisocyanate, PDI), 1,6-hexane diisocyanate (hexamethylene diisocyanate, HDI), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), 1,5-naphthalene diisocyanate, diisocyanatodiphenylmethane (2,2'-, 2,4'- and 4,4'-MDI or mixtures thereof), diisocyanatomethylbenzene (2,4- and 2,6-tolylene diisocyanate, TDI) and technical mixtures of the two isomers as well as 1,3- and / or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI), 1,4-paraphenylene diisocyanate (PPDI) and cyclohexyl diisocyanate (CHDI) and mixtures thereof.

[0026] The diisocyanate present according to the invention as unit M is very particularly preferably selected from the group consisting of 1,6-hexane diisocyanate (hexamethylene diisocyanate, HDI), 1,5-pentane diisocyanate (pentamethylene diisocyanate, PDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI) and mixtures thereof.

[0027] In a less preferred embodiment of the invention, in general formula (I), M represents at least one polyisocyanate unit. The polyisocyanate used for this purpose can be selected from the group consisting of aliphatic, cycloaliphatic, araliphatic, aromatic polyisocyanates, and mixtures thereof.

[0028] Examples of polyisocyanates present as unit M are selected from the group consisting of triisocyanates such as 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane or higher molecular weight oligomers with biuret, uretdione, isocyanurate, iminooxadiazinedione, allophanate, urethane and / or carbodiimide / uretonimine structural units obtainable by reacting di- or triisocyanates selected from the group consisting of 1,4-butane diisocyanate, 1,5-pentane diisocyanate (pentamethylene diisocyanate, PDI), 1,6-hexane diisocyanate (hexamethylene diisocyanate, HDI), 4-isocyanatomethyl-1,8-octane diisocyanate (triisocyanatononane, TIN), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-Tri-methyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), 1,5-naphthalene diisocyanate, diisocyanatodiphenylmethane (2,2'-, 2,4'- and 4,4'-MDI or mixtures thereof), diisocyanatomethylbenzene (2,4- and 2,6-tolylene diisocyanate,TDI) and technical mixtures of the two isomers as well as 1,3- and / or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI), 1,4-paraphenylene diisocyanate (PPDI), cyclohexyl diisocyanate (CHDI) and mixtures thereof.

[0029] In the compound of general formula (I), P each independently represents at least one polyol unit. According to the invention, the at least one polyol unit is preferably derived from a polyol.

[0030] According to the invention, polymeric polyols or low molecular weight polyols may be present.

[0031] According to the invention, compounds which contain at least one Zerewitinoff-active group, for example a hydroxyl or a thiol group, can be used as polyols P.

[0032] Polyols P which are particularly preferred according to the invention have an average OH or SH functionality of at least 1.5.

[0033] Polyols P preferred according to the invention are selected from the group consisting of diols, triols, tetraols, polyhydroxy compounds and mixtures thereof.

[0034] Polyols particularly preferred as unit P are selected from the group consisting of 1,2-ethanediol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, glycerol, trimethylolpropane, pentaerythritol, polyhydroxy compounds and mixtures thereof.

[0035] According to the invention, polyols P are preferably selected from the group consisting of polyether polyols, polyester polyols, polyurethane polyols, polysiloxane polyols, polycarbonate polyols, polybutadiene polyols, polyacrylate polyols, polymethacrylate polyols, copolymers of polyacrylate polyols and polymethacrylate polyols and mixtures thereof.

[0036] In a preferred embodiment, the at least one polyol P is a polymeric polyol, in particular a polyhydroxy compound. The polyhydroxy compounds preferably have weight-average molecular weights Mw of greater than 500 g / mol, particularly preferably 800 to 100,000 g / mol, in particular 1,000 to 50,000 g / mol, each measured by gel permeation chromatography (GPC) against a polystyrene standard.

[0037] The polyhydroxy compounds preferably have an OH number of 30 to 400 mg KOH / g, especially 100 to 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 the substance during acetylation. For the determination, the sample is boiled with acetic anhydride and pyridine, and the resulting acid is titrated with potassium hydroxide solution (DIN 53240-2 2:2007-11).

[0038] The glass transition temperatures, measured by DSC measurements according to DIN-EN-ISO 11357-2-2:2014-07, of the polyhydroxy compounds preferred according to the invention are preferably -150 to 100 °C, particularly preferably -120 to 80 °C.

[0039] According to the invention, the at least one polyol P is preferably selected from the group consisting of polyether polyols, polyester polyols, polyurethane polyols, polysiloxane polyols, polyacrylate polyols and mixtures thereof.

[0040] The polyether polyols preferably used according to the invention are accessible in a conventional manner by alkoxylation of suitable starter molecules under base catalysis or using double metal cyanide compounds (DMC compounds). Suitable starter molecules for the preparation of polyether polyols include, for example, simple, low-molecular-weight polyols, water, organic polyamines with at least two NH bonds, or any mixtures of such starter molecules.

[0041] Preferred starter molecules for the preparation of polyether polyols by alkoxylation, particularly by the DMC process, are, in particular, simple polyols such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 2-ethylhexanediol, glycerol, trimethylolpropane, pentaerythritol, as well as low-molecular-weight, hydroxyl-containing esters of such polyols with dicarboxylic acids of the type mentioned below, or low-molecular-weight ethoxylation or propoxylation products of such simple polyols, or any mixtures of such modified or unmodified alcohols. Alkylene oxides suitable for alkoxylation are, in particular, ethylene oxide and / or propylene oxide, which can be used in any order or as a mixture during the alkoxylation.

[0042] Polyester polyols suitable according to the invention are described, for example, in EP-A-0 994 1 17 and EP-A-1 273 640. Polyester polyols can be prepared in a known manner by polycondensation of low molecular weight polycarboxylic acid derivatives, for example succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimer fatty acid, trimer fatty acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, citric acid or trimellitic acid, with low molecular weight polyols, such as ethylene glycol, diethylene glycol, neopentyl glycol, hexanediol, butanediol, propylene glycol, glycerol, trimethylolpropane, 1,4-hydroxymethylcyclohexane, 2-methyl-1,3-propanediol, butanetriol-1,2,4, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol,Dibutylene glycol and polybutylene glycol, or by ring-opening polymerization of cyclic carboxylic acid esters such as epsilon-caprolactone. Furthermore, hydroxycarboxylic acid derivatives, such as lactic acid, cinnamic acid, or hydroxycaproic acid, can also be polycondensed to form polyester polyols. However, polyester polyols of oleochemical origin can also be used. Such polyester polyols can be produced, for example, by complete ring opening of epoxidized triglycerides of an at least partially olefinically unsaturated fatty acid-containing fat mixture with one or more alcohols having 1 to 12 carbon atoms, followed by partial transesterification of the triglyceride derivatives to form alkyl ester polyols having 1 to 12 carbon atoms in the alkyl radical.

[0043] Polyurethane polyols suitable for the invention are preferably prepared by reacting polyester polyol prepolymers with suitable di- or polyisocyanates and are described, for example, in EP-A-1 273 640 and EP-A-0 148 329. Polyurethane polyols prepared using HDI, PDI, IPDI, or H12MDI are preferred. The number-average molecular weight is preferably 500 to 2000 g / mol, and the average functionality is 2.0 to 3.5. Examples of suitable polyester polyols and suitable polyisocyanates are each mentioned above.

[0044] Polysiloxane polyols suitable according to the invention as polyol component P are described, for example, in WO-A-01 / 09260, wherein the polysiloxane polyols listed therein can preferably be used in combination with other polyhydroxy compounds, in particular those with higher glass transition temperatures.

[0045] The polyacrylate polyols most particularly preferred according to the invention are generally copolymers of acrylic acid and / or methacrylic acid with olefinically unsaturated monomers containing hydroxy groups and preferably have weight-average molecular weights Mw of 270 to 22,000 g / mol, preferably of 500 to 18,000 g / mol, particularly preferably of 800 to 12,000, measured in each case by gel permeation chromatography (GPC) against a polystyrene standard. The glass transition temperature of these copolymers is generally between -100 and 100 °C, in particular between -50 and 80 °C, measured in each case by DSC measurements according to DIN-EN-ISO 11357-2-2:2014-07.

[0046] Preferred poly(meth)acrylate polyols have an OH number of 60 to 250 mg KOH / g, in particular 70 to 200 mg KOH / g, and an acid number of 0 to 30 mg KOH / g. The acid number indicates the number of mg of potassium hydroxide required to neutralize 1 g of the respective compound (DIN EN ISO 2114:2002-06).

[0047] The preparation of suitable poly(meth)acrylate polyols is known per se to the person skilled in the art. They are obtained by radical polymerization of acrylic acid and / or methacrylic acid with hydroxyl-containing, olefinically unsaturated monomers and optionally other olefinically unsaturated monomers. Suitable olefinically unsaturated compounds include, for example:Ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, 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, 3,3,5-trimethylhexyl acrylate, 3,3,5-trimethylhexyl methacrylate, stearyl acrylate, stearyl methacrylate, lauryl acrylate or lauryl 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.

[0048] Suitable olefinically unsaturated monomers containing hydroxyl groups are in particular 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate and in particular 4-hydroxybutyl acrylate and / or 4-hydroxybutyl methacrylate.

[0049] Further monomer building blocks for the polyacrylate polyols that can be used are vinyl aromatic hydrocarbons, such as vinyltoluene, alpha-methylstyrene or in particular styrene, amides or nitriles of acrylic or methacrylic acid, vinyl esters or vinyl ethers, and in minor amounts, in particular acrylic and / or methacrylic acid.

[0050] Low molecular weight polyols P preferred according to the invention are derived, for example, from a polyhydric alcohol and / or ether or ester alcohol containing 2 to 14 carbon atoms, preferably 4 to 10 carbon atoms.

[0051] Preferably, the low molecular weight polyols P suitable according to the invention are selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, 1,10-decanediol, 1,12-dodecanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-bis(2-hydroxyethoxy)benzene, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxycyclohexyl)propane (perhydrobisphenol), 1,2,3-propanetriol, 1,2,4-butanetriol, 1,1,1-trimethylolethane, 1,2,6-hexanetriol, 1,1,1-trimethylolpropane (TMP), bis-(2-hydroxyethyl)-hydroquinone, 1,2,4-trihydroxycyclohexane, 1,3,5-trihydroxycyclohexane, 1,3,5-tris(2-hydroxyethyl)-isocyanurate, bis(hydroxymethyl)-tricyclo[5.2.1.02,6]-decane, 4,8-Bis(hydroxymethyl)tricyclo-[5.2.1.02,6]-decane, 5,8-Bis(hydroxymethyl)-tricyclo-[5.2.1.0(2,6)], di-trimethylolpropane, 2,2-bis(hydroxymethyl)-1,3-propanediol (pentaerythritol), 2,2,6,6-tetrakis(hydroxymethyl)-4-oxa-heptane-1,7-diol (dipentaerythritol), mannitol or sorbitol, low molecular weight ether alcohols such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol or dibutylene glycol, low molecular weight ester alcohols such as neopentyl glycol hydroxypivalate, and mixtures thereof.

[0052] Polyols P which are particularly preferred according to the invention are selected from the group consisting of 1,1,1-trimethylolpropane (TMP), a polyester composed of 1,6-hexanediol, neopentylglycol, 1,4-butanediol, adipic acid, 2,2,4-trimethyl-1,3-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, or a polyacrylate polyol composed of styrene, 1-decene, methyl methacrylate, acrylic acid, hydroxyethyl methacrylate, hydrophobic vinyl ester and mixtures thereof.

[0053] In the general formula (I), R each independently represents at least one polyisocyanate unit and / or at least one diisocyanate unit.

[0054] According to the invention, the compound of general formula (I) preferably contains at least one polyisocyanate unit as unit R.

[0055] According to the invention, the at least one polyisocyanate unit R is preferably derived from a polyisocyanate. Preferably, the at least one polyisocyanate is selected from the group consisting of aliphatic, cycloaliphatic, araliphatic, aromatic polyisocyanates, and mixtures thereof.

[0056] Particularly preferred according to the invention are polyisocyanates selected from the group consisting of triisocyanates such as 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane or, preferably higher molecular weight, oligomers with biuret, uretdione, isocyanurate, iminooxadiazinedione, allophanate, urethane and / or carbodiimide / uretonimine structural units obtainable by reacting di- or triisocyanates selected from the group consisting of 1,4-butane diisocyanate, 1,5-pentane diisocyanate (pentamethylene diisocyanate, PDI), 1,6-hexane diisocyanate (hexamethylene diisocyanate, HDI), 4-isocyanatomethyl-1,8-octane diisocyanate (triisocyanatononane, TIN), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-Tri-methyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), 1,5-naphthalene diisocyanate, diisocyanatodiphenylmethane (2,2'-, 2,4'- and 4,4'-MDI or mixtures thereof),Diisocyanatomethylbenzene (2,4- and 2,6-toluene diisocyanate, TDI) and technical mixtures of the two isomers as well as 1,3- and / or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI), 1,4-paraphenylene diisocyanate (PPDI), cyclohexyl diisocyanate (CHDI) and mixtures thereof.

[0057] The polyisocyanate used according to the invention as unit R is very particularly preferably selected from the group consisting of, preferably higher molecular weight, oligomers with biuret, uretdione, isocyanurate, iminooxadiazinedione, allophanate, urethane and / or carbodiimide / uretonimine structural units obtainable by reacting di- or triisocyanates selected from the group consisting of 1,5-pentane diisocyanate (pentamethylene diisocyanate, PDI), 1,6-hexane diisocyanate (hexamethylene diisocyanate, HDI), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), diisocyanatodiphenylmethane (2,2'-, 2,4'- and 4,4'-MDI or mixtures thereof), diisocyanatomethylbenzene (2,4- and 2,6-Toluene diisocyanate, TDI) and technical mixtures of the two isomers and mixtures thereof.

[0058] In a less preferred embodiment of the present invention, units R used are those derived from diisocyanates. These are selected, for example, from the group consisting of organic aliphatic, cycloaliphatic, araliphatic, aromatic diisocyanates, and mixtures thereof.

[0059] Examples of diisocyanates used as unit R are selected from the group consisting of 1,4-butane diisocyanate, 1,5-pentane diisocyanate (pentamethylene diisocyanate, PDI), 1,6-hexane diisocyanate (hexamethylene diisocyanate, HDI), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), 1,5-naphthalene diisocyanate, diisocyanatodiphenylmethane (2,2'-, 2,4'- and 4,4'-MDI or mixtures thereof), diisocyanatomethylbenzene (2,4- and 2,6-tolylene diisocyanate, TDI) and technical mixtures of the two isomers as well as 1,3- and / or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI), 1,4-paraphenylene diisocyanate (PPDI) and cyclohexyl diisocyanate (CHDI) and mixtures thereof.

[0060] In the general formula (I), Q represents at least one polysiloxane unit. According to the invention, the at least one polysiloxane unit Q present in the compound of the general formula (I) is preferably derived from a polysiloxane polyol, a polysiloxane polyamine, or a polysiloxane polythiol, in particular a polysiloxane polyol.

[0061] According to the invention, in principle, all polysiloxane polyols, polysiloxane polyamines or polysiloxane polythiols known to the person skilled in the art can be used to produce corresponding polysiloxane units in the compound of the general formula (I).

[0062] In a preferred embodiment of the present invention, the polysiloxane units Q present are based on compounds of the general formula (11) where R, R 4 , R 5 , R 6 , n, n 1< , m, m 1< and k have the following meanings: n and n 1< are independently 0 or greater than 0, preferably 10 to 200, particularly preferably 15 to 100 and (n+n 1< ) is less than 500, preferably less than 200, particularly preferably less than 100, m and m 1< are independently 0 or greater than 0, preferably 0 to 30, particularly preferably 0.1 to 25 and (m+m 1< ) is less than 60, preferably less than 30, particularly preferably less than 25, k 0 to 10, preferably 0 to 5, for example 0, 1, 2, 3, 4, or 5, R at least one radical selected from the group consisting of linear, cyclic or branched, aliphatic or aromatic, saturated or unsaturated carbon radicals having 1 to 20 C atoms and optionally heteroatoms selected from the group consisting of O, P, S, N, each optionally with a functional group selected from the halogen, hydroxy, amine, mercapto, carboxy, alkoxy, epoxy, alkylalkoxysilylalkyl or alkoxysilylalkyl group, in particular methyl, R 4 , R 5 ,R 6 is at least one radical selected from the group consisting of linear, cyclic or branched, aliphatic or aromatic, saturated or unsaturated carbon radicals having 1 to 20 C atoms and optionally heteroatoms selected from the group consisting of O, P, S, N, each optionally having a functional group selected from the halogen, hydroxy, amine, mercapto, carboxy, alkoxy, epoxy, alkylalkoxysilylalkyl or alkoxysilylalkyl group, -(CH 2 ) x" -O-(CH 2 -CH 2 O-) x -(CH 2 -CH(R')O-) y- (SO) z -R", wherein x is 0 to 100, preferably 1 to 5, x" is 0 to 100, preferably 1 to 4, y is 0 to 100, preferably 1 to 5, z is 0 to 100, preferably 0 to 1, R' is an optionally substituted alkyl or aryl group having 1 to 12 C atoms, for example substituted by alkyl radicals, aryl radicals or haloalkyl or haloaryl radicals, and R" is a hydrogen radical or an alkyl group having 1 to 4 C atoms, a group-C(O)-R‴ with R‴ = alkyl radical,a group -CH 2 -O-R', an alkylaryl group or a group -C(O)NH-R', SO is a styrene oxide radical -CH(C 6 H 5 )-CH 2 -O-, , wherein at least two, preferably 2 to 5, particularly preferably 2, radicals selected from R, R 4 , R 5 and / or R 6 carry at least one hydroxyl, amine and / or thiol group, preferably at least one hydroxyl group.

[0063] In the compounds of the general formula (II), the various monomer units of the siloxane chain and / or the polyoxyalkylene chain can be constructed in blocks or can be subject to a statistical distribution.

[0064] Within the scope of the present invention, all index numbers and value ranges specified according to the invention can be understood as mean values ​​of the possible statistical distribution of the structures actually present and / or their mixtures. According to the invention, decimal numbers (decimal points), for example 1.2, can also occur as index numbers. In this case, as the mean value of a mixture containing compounds with different index numbers.

[0065] In a preferred embodiment, in the general formula (II) R is methyl, ethyl and / or phenyl.

[0066] More preferably, in the general formula (II), R 4 , R 5 and / or R 6 are, for example, with m = 6 to 20, preferably 8 to 18, n = 2 to 18, preferably 4 to 8, o = 0 to 30, preferably 2 to 20, in particular 5 to 15, p = 0 to 30, preferably 0 to 10, q = 0 to 30, preferably 2 to 20, in particular 5 to 15, r = 0 to 30, preferably 0 to 10, s = 0 to 10, preferably 1 to 5, t = 1 to 20, preferably 1 to 10, u = 1 to 10, preferably 2 to 4, v = 1 to 10, preferably 2 to 5, w = 1 to 6, preferably 1 to 3, x = 1 to 6, preferably 2 to 4, y = 1 to 10, preferably 1 to 3.

[0067] The functionality of the polysiloxane polyols, polysiloxane polyamines or polysiloxane polythiols preferably used according to the invention is, for example, 2 to 6, particularly preferably 2, 3, 4, 5 or 6, very particularly 2.

[0068] The polysiloxane polyols, polysiloxane polyamines, or polysiloxane polythiols preferably used according to the invention contain, for example, 1 to 50, particularly preferably 2 to 30, and most preferably 3 to 20, repeating units. According to the invention, a "siloxane" is understood to mean a group that contains a basic structure containing two or more -SiO groups.

[0069] According to the invention, the polysiloxane polyol used is very particularly preferably an α,ω-hydroxypropyl-terminated polydimethylsiloxane having an OH content of 1 to 10, preferably 2 to 8 wt.%, a molecular weight of 200 to 2000 g / mol, preferably 400 to 1000 g / mol and a solids content of 100 wt.%, so that after reaction with the NCO groups of the diisocyanates and / or polyisocyanates of the unit M, a corresponding polysiloxane unit Q is present.

[0070] The present invention preferably relates to the polysiloxane prepolymer according to the invention, wherein the at least one polysiloxane unit is present in an amount of 0.1 to 5 wt.%, based on the total polysiloxane prepolymer.

[0071] Furthermore, the present invention preferably relates to the polysiloxane prepolymer according to the invention, wherein the polysiloxane prepolymer according to the invention has a number-average molecular weight Mn of <4000 g / mol, preferably of >450 g / mol and <3000 g / mol, particularly preferably of >650 g / mol and <2500 g / mol, and very particularly preferably of >800 g / mol and <2500 g / mol. The number-average molecular weight Mn is determined by gel permeation chromatography (GPC) in tetrahydrofuran at 23°C. The procedure is according to DIN 55672-1:2016-03: "Gel permeation chromatography, Part 1 - Tetrahydrofuran as eluent" (SECurity GPC system from PSS Polymer Service, flow rate 0.6 ml / min; columns: 2×PSS SDV (100A), 2×PSS SDV (50A), 8×300 mm, 5 µm; RID detector (RI-Agilent 1260).

[0072] Polystyrene samples of known molecular weight are used for calibration. The calculation of the number-average molecular weight is carried out using software.

[0073] In the general formula (I), r represents the number of R units present, which in turn are selected from the above-mentioned group. In the general formula (I), r preferably independently represents a number from 1 to 30, particularly preferably 1 to 20, further preferably 1 to 5, and most preferably r is 1.

[0074] In the general formula (I), m represents the number of units M present, which in turn are selected from the above-mentioned group. In the general formula (I), m preferably independently represents a number from 1 to 30, particularly preferably 1 to 20, further preferably 1 to 5, and most preferably m is 1.

[0075] In the general formula (I), p describes the number of units P present, which in turn are selected from the above-mentioned group. In the general formula (I), p preferably independently represents a number from 1 to 30, particularly preferably 1 to 20, further preferably 1 to 5, and most preferably p is 1.

[0076] In the general formula (I), q describes the number of Q units present, which in turn are selected from the above-mentioned group. In the general formula (I), q preferably independently represents a number from 1 to 30, particularly preferably 1 to 20, further preferably 1 to 5, and most preferably q is 1.

[0077] In the general formula (I), t describes the number of units -[(M) m -(P) p -(R) r ] present, which are attached to the unit(s) Q. In the general formula (I), t preferably independently represents a number from 2 to 5, particularly preferably 2, 3 or 4, and most preferably t is 2.

[0078] According to the invention, a monofunctional compound can additionally be used as the compound containing siloxane groups, for example a poly(dimethylsiloxane)-propylhydroxycopolymer, in particular heptamethyl-2-(3-hydroxypropyl)-trisiloxane with a functionality of 1 and a molecular weight of 280 g / mol.

[0079] The present invention also relates to a process for producing an NCO-terminated polysiloxane prepolymer according to the invention, comprising at least the following steps: (A) reacting at least one polysiloxane polyol, polysiloxane polyamine and / or polysiloxane polythiol with at least one diisocyanate and / or at least one polyisocyanate to obtain at least one NCO-terminated polysiloxane, (B) optionally removing excess at least one diisocyanate and / or at least one polyisocyanate, (C) reacting the at least one NCO-terminated polysiloxane from step (A) or (B) with at least one polyol, (D) reacting the product obtained in step (C) with at least one diisocyanate or at least one polyisocyanate to obtain the NCO-terminated polysiloxane prepolymer.

[0080] The individual steps of the method according to the invention are described in detail below.

[0081] Step (A) of the process according to the invention comprises the reaction of at least one polysiloxane polyol, polysiloxane polyamine and / or polysiloxane polythiol, preferably at least one polysiloxane polyol, with at least one diisocyanate and / or at least one polyisocyanate, preferably at least one diisocyanate, in order to obtain at least one NCO-terminated polysiloxane.

[0082] Step (A) of the process according to the invention can generally be carried out by any method known to the person skilled in the art. Preferably, step (A) of the process according to the invention can be carried out in apparatus known to the person skilled in the art, for example, stirred reactors with inlet and outlet lines for reactants and products. Optionally, step (A) of the process according to the invention can be carried out in the absence of water and air, for example, in a dry atmosphere of nitrogen or a noble gas, for example, helium or argon.

[0083] Step (A) of the process according to the invention can be carried out, for example, by mixing the substrates, in particular the at least one diisocyanate and / or the at least one polyisocyanate and the at least one polysiloxane polyol, polysiloxane polyamine and / or polysiloxane polythiol, with one another and reacting them.

[0084] In a preferred embodiment, step (A) of the process according to the invention is carried out by initially introducing the at least one diisocyanate and / or the at least one polyisocyanate. According to the invention, the at least one diisocyanate and / or the at least one polyisocyanate can be initially introduced in a solvent or without a solvent. Suitable solvents for this reaction step are preferably those which do not participate in the reaction per se, for example ethyl acetate, butyl acetate, methoxypropyl acetate, solvent naphtha (Solvesso 100) and / or methyl ethyl ketone. Step (A) of the process according to the invention is preferably carried out in the absence of a solvent. According to the invention, the initially introduced at least one diisocyanate and / or the at least one polyisocyanate is preferably heated to a temperature above room temperature, for example 60 to 120 °C, preferably 80 to 110 °C.

[0085] More preferably, the at least one polysiloxane polyol, polysiloxane polyamine and / or polysiloxane polythiol is added to the at least one diisocyanate and / or at least one polyisocyanate provided.

[0086] The ratio of NCO groups present in the reaction mixture to the NCO-reactive groups, ie OH, SH and / or NH groups, in step (A) of the process according to the invention is generally 1 to 50, preferably 2 to 30, particularly preferably 2 to 20.

[0087] The resulting reaction mixture is generally stirred until complete conversion has occurred. The reaction mixture is preferably stirred for 1 to 8 hours, preferably 2 to 6 hours.

[0088] The reaction according to step (A) of the process according to the invention is preferably carried out at a temperature of 60 to 120 °C, particularly preferably 80 to 110 °C.

[0089] After step (A) of the process according to the invention, a reaction mixture is obtained which contains the reaction product of the at least one polysiloxane polyol, polysiloxane polyamine and / or polysiloxane polythiol with at least one diisocyanate or at least one polyisocyanate, ie, at least one NCO-terminated polysiloxane.

[0090] According to the invention, the reaction mixture obtained in step (A) can either be used directly in step (C) of the process according to the invention. This is preferably done when the ratio of NCO groups to NCO-reactive groups in the reaction mixture was adjusted such that the NCO-terminated polysiloxane was obtained, but there was no excess of at least one diisocyanate and / or at least one polyisocyanate, i.e., there was no excess of at least one diisocyanate and / or at least one polyisocyanate in the reaction mixture obtained after step (A).

[0091] In a preferred embodiment of the present invention, the reaction mixture obtained in step (A) of the process according to the invention is transferred to step (B) of the process according to the invention, particularly preferably without further intermediate steps.

[0092] The optional step (B) of the process according to the invention comprises the removal of excess at least one diisocyanate or at least one polyisocyanate.

[0093] Step (B) is preferably carried out. By removing excess at least one diisocyanate or at least one polyisocyanate in step (B) of the process according to the invention, the NCO-terminated polysiloxane polyol is obtained which is not contaminated with at least one diisocyanate and / or at least one polyisocyanate. Carrying out step (B) according to the invention therefore makes it possible to obtain the desired target compound according to the invention, the NCO-terminated polysiloxane prepolymer, in high purity, uniformity, and with a higher molecular weight than alternative preparation processes.

[0094] According to the invention, the content of at least one diisocyanate or at least one polyisocyanate, preferably at least one diisocyanate, in the reaction mixture after step (B) is preferably at most 5 wt.%, preferably 1 to 0.01 wt.%.

[0095] Step (B) of the process according to the invention can, in principle, be carried out by any method known to the person skilled in the art. The present invention preferably relates to the process according to the invention, wherein step (B) is carried out by thin-film evaporation, phase separation, precipitation, or combinations thereof.

[0096] Step (B) of the process according to the invention is preferably carried out by thin-film evaporation. More preferably, the thin-film evaporation is carried out at a temperature of 50 to 200 °C, preferably 80 to 120 °C. Furthermore, the thin-film evaporation is carried out at a pressure of preferably 0.001 to 500 mbar(a), particularly preferably 0.01 to 200 mbar(a).

[0097] Step (B) of the process according to the invention can be carried out in any apparatus known to the person skilled in the art, in particular in a thin-film evaporator or apparatus suitable for phase separation or precipitation.

[0098] The NCO-terminated polysiloxane polyol obtained after step (A) or (B), preferably after step (B), has an NCO content of generally 1 to 20 wt.%, preferably 4 to 18 wt.%.

[0099] The NCO-terminated polysiloxane polyol obtained after step (A) or (B), preferably after step (B), has a concentration of generally 100 to 50 wt.%, preferably 100 to 75 wt.%. This means that the desired product is preferably obtained without impurities and solvents.

[0100] The NCO-terminated polysiloxane polyol obtained after step (A) or (B), preferably after step (B), has a viscosity of generally 50 to 4000 mPa·s, preferably 100 to 2500 mPa·s, particularly preferably 100 to 1000 mPa·s.

[0101] Step (C) of the process according to the invention comprises the reaction of the at least one NCO-terminated polysiloxane from step (A) or (B) with at least one polyol.

[0102] Step (C) of the process according to the invention can generally be carried out by any method known to the person skilled in the art. According to the invention, the NCO-terminated polysiloxane from step (A) or (B) is preferably mixed with the at least one polyol and reacted. Suitable and preferred polyols according to the invention have already been mentioned above.

[0103] The molar ratio of the NCO groups present in the reaction mixture according to step (C) of the process according to the invention to the OH, NH and / or SH groups present in the at least one polyol used is preferably 0.001 to 0.9, particularly preferably 0.01 to 0.8.

[0104] Step (C) of the process according to the invention can be carried out in the presence or absence of a solvent. In a preferred embodiment, step (C) of the process according to the invention is carried out in the presence of a solvent. The solvent used in step (C) of the process according to the invention is preferably selected from the group consisting of esters, for example 1-methoxy-2-propyl acetate (MPA), butyl acetate (BA), dibasic esters, ketones, for example methyl ethyl ketone, ethers, for example diethyl ether, and mixtures thereof.

[0105] In the reaction mixture according to step (C) of the process according to the invention, the components are present in total in a concentration of 20 to 80 wt.%, preferably 30 to 70 wt.%, in each case solids content based on the total solution.

[0106] The reaction in step (C) of the process according to the invention can be carried out in the presence of at least one catalyst. Suitable catalysts are known to the person skilled in the art and are selected, for example, from the group of organotin compounds; dibutyltin laurate is particularly suitable. If a catalyst is used in step (C) of the process according to the invention, it is preferably present in a concentration of 0.01 to 0.1 wt. %, based on the reaction mixture.

[0107] Step (C) of the process according to the invention can be carried out in devices known to those skilled in the art, for example stirred reactors with appropriate inlets and outlets. Furthermore, step (C) of the process according to the invention can preferably be carried out in an inert atmosphere, for example in an atmosphere of nitrogen or a noble gas, for example helium or argon.

[0108] Step (C) of the process according to the invention is preferably carried out at a temperature of 20 to 100 °C, preferably 40 to 80 °C. In general, step (C) of the process according to the invention is carried out at atmospheric pressure or at a pressure slightly elevated relative to atmospheric pressure by using an inert gas.

[0109] Step (C) of the process according to the invention is generally carried out until all NCO groups present have reacted, i.e., have reacted with an OH or SH group. Preferably, step (C) of the process according to the invention is carried out until the NCO group content in the reaction mixture is less than 0.5 wt. %, particularly preferably less than 0.2 wt. %, based in each case on the total reaction mixture. Most preferably, no NCO groups are present in the reaction mixture, i.e., the NCO group content is below the analytical detection limit known to the person skilled in the art.

[0110] In a preferred embodiment of the process according to the invention, the reaction mixture obtained after completion of step (C) can be transferred directly to step (D) of the process according to the invention. If appropriate, the reaction mixture can be worked up after step (C) and before step (D).

[0111] Step (D) of the process according to the invention comprises the reaction of the product obtained in step (C) with at least one polyisocyanate and / or at least one diisocyanate, preferably with at least one polyisocyanate, in order to obtain the NCO-terminated polysiloxane prepolymer.

[0112] Step (D) of the process according to the invention can generally be carried out by any method known to the person skilled in the art. In a preferred embodiment of the present invention, the at least one polyisocyanate and / or the at least one diisocyanate, preferably the at least one polyisocyanate, is added to the reaction mixture obtained from step (C).

[0113] According to the invention, the molar ratio of the OH or SH groups present in the reaction mixture used in step (D) to the NCO groups added in step (D) is preferably 1.1 to 20, particularly preferably 2 to 12.

[0114] Step (D) of the process according to the invention is preferably carried out in the presence of a solvent. In a preferred embodiment of the process according to the invention, the reaction mixture used in step (D) already contains solvent from step (C). In a further preferred embodiment of the present invention, solvent is added in step (D) of the process according to the invention. In a preferred embodiment, sufficient solvent is added in step (D) that the concentration of the dissolved components in the reaction mixture is 20 to 80% by weight, preferably 30 to 70% by weight, based in each case on the total reaction mixture. Solvents suitable for step (D) have already been mentioned with regard to step (C).

[0115] Step (D) of the process according to the invention can be carried out in devices known to those skilled in the art, for example stirred reactors with appropriate inlets and outlets. Furthermore, step (D) of the process according to the invention can preferably be carried out in an inert atmosphere, for example in an atmosphere of nitrogen or a noble gas, for example helium or argon.

[0116] Step (D) of the process according to the invention is preferably carried out at a temperature of 20 to 100 °C, preferably 40 to 80 °C. In general, step (D) of the process according to the invention is carried out at atmospheric pressure or, by using an inert gas, at a pressure slightly elevated above atmospheric pressure.

[0117] After step (D) of the process according to the invention, the desired NCO-terminated polysiloxane prepolymer, in particular of general formula (I), is obtained. After step (D), optional workup steps, for example, removal of the solvent present, such as ethyl acetate, methoxypropyl acetate, butyl acetate, solvent naphtha (Solvesso 100), or mixtures thereof, may be carried out.

[0118] The NCO-terminated polysiloxane prepolymer obtained after step (D) has an NCO content of generally 0.1 to 17 wt.%, preferably 2 to 14 wt.%.

[0119] The NCO-terminated polysiloxane prepolymer obtained after step (D) has a solids content of generally 20 to 80 wt.%, preferably 30 to 70 wt.%.

[0120] The NCO-terminated polysiloxane prepolymer obtained after step (D) has a Hazen color number of generally 0 to 300, preferably 10 to 150.

[0121] The present invention further provides an NCO-terminated polysiloxane prepolymer obtainable or produced by the process according to the invention. The NCO-terminated polysiloxane prepolymer according to the invention is characterized in particular by the fact that, on the one hand, the coatings obtainable therefrom exhibit significantly better residual gloss and reflow than comparable systems without the NCO-terminated polysiloxane prepolymer according to the invention and, on the other hand, that, as surface-active substances, they can enable a reduced use or even elimination of leveling additives. The measurement of residual gloss and reflow is preferably carried out as indicated in the examples section, and the observation of the reduction in leveling additives is preferably carried out by visual assessment of the coating to determine whether or not an orange peel effect has formed.

[0122] The present invention further relates to a formulation comprising at least one NCO-terminated polysiloxane prepolymer according to the invention, preferably in an amount of 5 to 70 wt. %, based on the total formulation. In particular, the formulation according to the invention is a coating formulation.

[0123] Apart from the NCO-terminated polysiloxane prepolymer according to the invention, corresponding formulations are known per se to the person skilled in the art.

[0124] The coating formulation according to the invention can preferably be in the form of a two-component formulation known per se to the person skilled in the art.

[0125] A 2-component formulation according to the invention preferably contains in the first component at least one polyhydroxy compound and optionally additives (component A) and in the second component at least one NCO-terminated polysiloxane prepolymer according to the invention, at least one polyisocyanate and optionally additives (component B).

[0126] According to a preferred embodiment of the invention, the coating formulation according to the invention, in particular the 2-component formulation according to the invention, is a formulation for a clear and / or topcoat layer.

[0127] A basecoat may be present beneath the clearcoat and / or topcoat layer according to the invention. The composition, requirements, and processing of basecoat formulations are known to those skilled in the art and are described, for example, in the specifications of automobile manufacturers or, for example, in the article "A Question of Attitude," published in "Farbe und Lack 07 / 2003" (Vinzentz-Verlag), pages 1 to 3, further in U. Poth, Automotive Coatings Formulation, Vinventz-Verlag 2008, ISBN 9783866309043, pages 137 to 163 and 213 to 215, or in U. Kuttler, Principles of Automotive OEM Coatings, Allnex Belgium SA.

[0128] Component A of the two-component formulation according to the invention preferably contains at least one polyhydroxy compound. The polyhydroxy compound is preferably selected from the group consisting of polyester polyols, polyurethane polyols, polysiloxane polyols, polycarbonate polyols, polyacrylate polyols, and mixtures thereof, preferably selected from the group consisting of polyester polyols, polyacrylate polyols, polyurethane polyols, and mixtures thereof. Corresponding polyhydroxy compounds are known per se to the person skilled in the art and are described, for example, further above in this document.

[0129] The polycarbonate polyols in question are obtainable by reacting carbonic acid derivatives, e.g., diphenyl carbonate, dimethyl carbonate, or phosgene, with diols. Examples of such diols include ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A, tetrabromobisphenol A, and also lactone-modified diols. The diol component preferably contains 40 to 100% by weight of 1,6-hexanediol and / or hexanediol derivatives, preferably those which have ether or ester groups in addition to terminal OH groups, e.g. products which are obtained by reacting 1 mol of hexanediol with at least 1 mol, preferably 1 to 2 mol, of ε-caprolactone or by etherification of hexanediol with itself to form di- or trihexylene glycol.Polyether polycarbonate polyols can also be used.

[0130] Polycarbonate polyols based on dimethyl carbonate and hexanediol and / or butanediol and / or ε-caprolactone are preferred. Polycarbonate polyols based on dimethyl carbonate and hexanediol and / or ε-caprolactone are particularly preferred.

[0131] Suitable polyols are, for example, the known polyacetal polyols obtainable by reacting simple glycols, such as diethylene glycol, triethylene glycol, 4,4'-di((2-hydroxyethoxy)phenyl)-dimethylmethane (adduct of 2 mol of ethylene oxide with bisphenol A) or hexanediol, with formaldehyde or polyacetals produced by polycondensation of cyclic acetals, such as trioxane.

[0132] Other suitable polyols are, for example, the special polyols described in EP-A 0 689 556 and EP-A 0 937 110, for example those obtainable by reacting epoxidized fatty acid esters with aliphatic or aromatic polyols with epoxide ring opening.

[0133] Polybutadienes containing hydroxyl groups can also serve as polyols.

[0134] The polymeric polyols can be used individually or in any mixture. They can be present in solvent-free form or dissolved in common solvents.

[0135] Furthermore, additives may be present in component (A) of the two-component formulation according to the invention. Such additives are known per se to the person skilled in the art.

[0136] According to the invention, the optionally present additive is selected from the group consisting of catalysts, solvents, light stabilizers such as UV absorbers and hindered amines (HALS), stabilizers, for example UV stabilizers, fillers, anti-settling agents, defoamers, anti-cratering agents, wetting agents, leveling agents, film-forming auxiliaries, reactive diluents, substances for rheology control, slip additives, components that prevent soiling and / or improve the cleanability of the cured coatings, matting agents, antioxidants, pigments, and mixtures thereof. UV stabilizers, antioxidants, leveling agents, fillers, and / or pigments are preferred.

[0137] Catalysts suitable according to the invention are suitable for catalyzing the reaction of component A with component B. Such catalysts are known to the person skilled in the art. Particularly suitable are tin catalysts, bismuth catalysts, zinc catalysts, zirconium catalysts and amine bases. Particularly suitable are, for example, zinc compounds, e.g. zinc(II) stearate, zinc(II) n-octanoate, zinc(II) 2-ethyl-1-hexanoate, zinc(II) naphthenate, zinc chloride, zinc 2-ethylcaproate or zinc(II) acetylacetonate, tin compounds, e.g. B. tin (II) n-octanoate, tin (II) 2-ethyl-1-hexanoate, tin (II) laurate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, tin (II) ethyl caproate, di-butyltin (IV) dilaurate, dibutyltin dimaleate or dioctyltin diacetate, Zirconium compounds, e.g. b.Zirconium (IV) 2-ethyl-1-hexanoate, zirconium (IV) isopropylate, zirconium (IV) n-butylate, zirconium (IV) 2-ethylhexanoate, zirconium octanoate, zirconium (IV) neodecanoate, zirconium (IV) naphthenate or zirconium (IV) acetylacetonate, bismuth(III) 2-ethylhexanoate and bismuth(III) octoate.

[0138] The catalyst is preferably used in amounts of 0.001 to 0.5 wt.%, more preferably in amounts of 0.01 to 0.3 wt.%, in each case based on the total weight of compound A of the first component.

[0139] Component A may further preferably contain at least one solvent. In general, all solvents known to those skilled in the art are suitable. Particularly suitable are aromatic and aliphatic solvents, preferably selected from the group consisting of butyl acetate, 1-methoxy-2-propyl acetate, 3-methoxy-1-butyl acetate, ethyl acetate, dibasic esters, propylene n-butyl ether, methyl ethyl ketone, toluene, xylene, solvent naphtha (hydrocarbon mixture), and mixtures thereof. The solvent is preferably present in an amount of 30 to 90 wt. %, particularly preferably 45 to 70 wt. %, based on the total weight of component A.

[0140] UV stabilizers suitable according to the invention can preferably be selected from the group consisting of piperidine derivatives, such as 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-1,2,2,6,6-pentamethylpiperidine, bis-(2,2,6,6-tetra-methyl-4-piperidyl)-sebacate, bis(1,2,2,6,6-pentamethyl-1-4-piperidinyl)-sebacate, bis-(2,2,6,6-tetramethyl-4-piperidyl)-su-berate, bis-(2,2,6,6-tetramethyl-4-piperidyl)-dodecanedioate; benzophenone derivatives such as 2,4-dihydroxy, 2-hydroxy-4-methoxy, 2-hydroxy-4-octoxy, 2-hydroxy-4-dodecyloxy or 2,2'-dihydroxy-4-dodecyloxy-benzophenone; Benztriazole derivatives, such as2-(2H-Benzotriazol-2-yl)-4,6-di-tert-pentylphenol, 2-(2H-Benzotriazol-2-yl)-6-dodecyl-4-methylphenol, 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(5-Chlor-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-Benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, Isooctyl-3-(3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenylpropionat), 2-(2H-Benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol, 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(5-Chlor-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol; Oxalaniliden, wie z.B. 2-Ethyl-2'-ethoxy- oder 4-Methyl-4'-methoxyoxalanilid; Salicylsäureestern, wie z.B. Salicylsäurephenylester, Salicylsäure-4-tert-butylphenylester, Salicylsäure-4-tert-octylphenylester; Zimtsäureesterderivaten, z.B.Methyl α-cyano-β-methyl-4-methoxycinnamate, butyl α-cyano-β-methyl-4-methoxycinnamate, ethyl α-cyano-β-phenylcinnamate, isooctyl α-cyano-β-phenylcinnamate; and malonic ester derivatives, e.g., dimethyl 4-methoxybenzylidenemalonate, diethyl 4-methoxybenzylidenemalonate, dimethyl 4-butoxybenzylidenemalonate, DL-alpha-tocopherol, tocopherol, cinnamic acid derivatives, cyanoacrylates, and mixtures thereof. These preferred UV stabilizers can be used individually or in any combination. Particularly preferred UV stabilizers are available under the trade names Tinuvin®< 292 and Tinuvin®< 1130 from BASF SE.

[0141] Sterically hindered amines (often referred to as HALS or HAS compounds; Hindered Amine (Light) Stabilizer) can serve as suitable radical scavengers. These are selected from the group consisting of 2,2,6,6-tetramethylpiperidine, 2,6-di-tert-butylpiperidine or their derivatives, e.g. bis-(2,2,6,6-tetra-methyl-4-piperidyl)sebacinate, and mixtures thereof. These are available, for example, as Tinuvin ®< and Chimaassorb ®< brands from BASF SE. N-alkylated radical scavengers are, for example, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate (e.g. Tinuvin ®< 144 from BASF); a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate (e.g. Tinuvin ®< 292 from BASF SE); or which are N-(o-alkylated), such as decanedioic acid bis-(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester, reaction products with 1,1-dimethylethyl hydroperoxide and octane (e.g.Tinuvin ®< 123 from BASF SE), and especially the HALS triazine, reaction products of 2-aminoethanol with cyclohexane and peroxidized N-butyl-2,2,6,6-tetramethyl-4-piperidinamine-2,4,6-trichloro-1,3,5-triazine reaction product" (e.g. Tinuvin ®< 152 from BASF SE).

[0142] Optionally, one or more of the UV stabilizers of component A mentioned by way of example are used, preferably in amounts of 0.001 to 3.0% by weight, particularly preferably 0.01 to 2% by weight, based on the total weight of compound A.

[0143] Antioxidants suitable according to the invention are preferably sterically hindered phenols, which can preferably be selected from the group consisting of 2,6-di-tert-butyl-4-methylphenol (ionol), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triethylene glycol bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, 2,2'-thio-bis(4-methyl-6-tert-butylphenol) and 2,2'-thio-diethyl-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. These can be used individually or in any combination with one another if required. Antioxidants are preferably used in amounts of 0.001 to 3.0 wt.%, particularly preferably 0.02 to 2.0 wt.%, each calculated as the total amount of antioxidants used in relation to the total weight of compound A.

[0144] To improve substrate wetting, suitable leveling agents, for example organically modified siloxanes such as polyether-modified siloxanes, polyacrylates, and / or fluorosurfactants, may optionally be present. These leveling agents are preferably present in amounts of 0.01 wt.% to 3 wt.%, preferably 0.01 wt.% to 2 wt.%, particularly preferably 0.05 to 1.5 wt.%, calculated as the total amount of leveling agents used relative to the total weight of compound A. Preferred leveling agents are commercially available under the trade names BYK 141 and BYK 311 from Altana.

[0145] The polyisocyanates present in component B of the two-component formulation according to the invention are selected, for example, from the group mentioned above for the synthesis of the polysiloxane prepolymer according to the invention. Preferred polyisocyanates include all higher molecular weight oligomers with biuret, uretdione, isocyanurate, iminooxadiazinedione, allophanate, urethane, and / or carbodiimide / uretonimine structural units obtainable by reacting di- or triisocyanates selected from the group consisting of PDI, HDI, HDI, H12MDI, IPDI, and mixtures thereof. These polyisocyanates are generally present in an amount of 5 to 50 wt. %, preferably 5 to 25 wt. %, based in each case on the total formulation consisting of component A and component B.

[0146] Furthermore, component B of the two-component formulation according to the invention contains the NCO-terminated polysiloxane prepolymer of general formula (I) according to the invention. This is present, for example, in an amount of generally 50 to 95 wt. %, preferably 75 to 95 wt. %, based in each case on component B.

[0147] Preferably, component B does not contain any further additives besides the compounds mentioned.

[0148] According to the invention, the two-component formulation according to the invention can also be an aqueous formulation. In this embodiment, the above-mentioned at least one solvent in component A and / or component B of the two-component formulation according to the invention is replaced by water.

[0149] In addition to the NCO-terminated siloxane prepolymer according to the invention, the polyisocyanate component A) may optionally also contain polyisocyanates with aliphatically, cycloaliphatically, araliphatically, and / or aromatically bound isocyanate groups, which may also contain siloxane chains. These further polyisocyanates are, in particular, the known lacquer isocyanates with uretdione, isocyanurate, iminooxadiazinedione, urethane, allophanate, biuret, and / or oxadiazinetrione structures, as described by way of example in Laas et al., J. Prakt. Chem. 336, 1994, 185-200, in DE-A 1 670 666, DE-A 3 700 209, DE-A 3 900 053, EP-A 0 330 966, EP-A 0 336 205, EP-A 0 339 396 and EP-A 0 798 299. The compounds described above as unit R are preferably used for this purpose.

[0150] Particularly preferred further polyisocyanates in the polyisocyanate component A) are those of the type mentioned with exclusively aliphatically and / or cycloaliphatically bound isocyanate groups, in particular those based on PDI, HDI and / or IPDI.

[0151] These further polyisocyanates are optionally used in the coating compositions according to the invention in amounts of up to 70% by weight, preferably up to 60% by weight, particularly preferably up to 50% by weight, based on the total amount of the polyisocyanate component A) consisting of at least one NCO-terminated siloxane prepolymer and optionally further polyisocyanates.

[0152] The formulations according to the invention, in particular paint formulations, can contain as binder component any aqueous polymer dispersions B) which preferably carry groups reactive towards isocyanate groups, particularly preferably hydroxyl groups and / or amino groups.

[0153] Suitable aqueous polymer dispersions B) include all polymer dispersions commonly used in aqueous 2K PU coating technology. These include, for example, the usual aqueous or water-dispersible polyacrylate resins, polyester resins, polyurethane resins, polyurea resins, polycarbonate resins, or polyether resins, as described, for example, in EP-A 0 358 979, EP-A 0 469 389, EP-A 0 496 205, EP-A 0 557 844, EP-A 0 583 728, WO 94 / 03511, WO 94 / 20559, WO 94 / 28043, or WO 95 / 02005. The use of any hybrid dispersions or any mixtures of different polymer dispersions is also possible.

[0154] Examples of suitable hydroxy-functional polyacrylate dispersions B1) are the known so-called secondary polyacrylate dispersions, which can be prepared in a manner known per se by copolymerization of olefinically unsaturated monomers having hydroxyl groups with hydroxyl-free olefinic monomers in organic solvents, neutralization of possibly incorporated ionic groups and dispersion in water.

[0155] Examples of suitable monomers for preparing the secondary polyacrylate dispersions B1) are, for example, vinyl and vinylidene monomers such as styrene, α-methylstyrene, o- and / 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 18 carbon atoms, such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, 3,3,5-trimethylhexyl acrylate, stearyl acrylate, lauryl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, 4-tert-butycyclohexyl acrylate, norbornyl acrylate, isobornyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, amyl methacrylate, hexyl methacrylate 2-ethylhexyl methacrylate, isooctyl methacrylate, 3,3,5-trimethylhexyl methacrylate,Stearyl methacrylate, lauryl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, 4-tert-butylcyclohexyl methacrylate, norbornyl methacrylate or isobornyl methacrylate, diesters of fumaric acid, itaconic acid or maleic acid alcohols with 4 to 8 carbon atoms, acrylamide, methacrylamide, vinyl esters of alkane monocarboxylic acids with 2 to 5 carbon atoms, such as vinyl acetate or vinyl propionate, carboxy-functional radically polymerized monomers, such as acrylic acid, methacrylic acid, 1-carboxyethyl acrylate, crotonic acid, fumaric acid, maleic acid (anhydride), itaconic acid or monoalkyl esters of dibasic acids and / or anhydrides, such as monoalkyl maleates, hydroxyalkyl esters of acrylic acid and methacrylic acid with 2 to 6 carbon atoms in the hydroxyalkyl radicals, such as 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-Hydroxybutyl, 4-Hydroxybutyl, trimethylolpropane mono- or pentaerythritol monoacrylate or methacrylate,Hydroxyl monomers containing alkylene oxide units, such as addition products of ethylene oxide, propylene oxide or butylene oxide with acrylic acid or methacrylic acid, as well as any mixtures of such monomers mentioned as examples.

[0156] Likewise suitable olefinically unsaturated monomers for preparing the secondary polyacrylate dispersions B1) are vinyl monomers containing alkylene oxide units, such as condensation products of acrylic acid or methacrylic acid with oligoalkylene oxide monoalkyl ethers, and monomers with further functional groups such as, for example, epoxy groups, alkoxysilyl groups, urea groups, urethane groups, amide groups or nitrile groups, and (meth)acrylate monomers and / or vinyl monomers with a functionality of two or more, such as, for example, hexanediol di(meth)acrylate, which can be used in small amounts of, for example, up to 3% by weight, based on the sum of the monomers.

[0157] Preferred olefinically unsaturated monomers for the preparation of secondary polyacrylate dispersions B1) are methyl methacrylate, styrene, acrylic acid, methacrylic acid, butyl acrylate, butyl methacrylate, ethyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate or hydroxybutyl methacrylate.

[0158] In the secondary polyacrylate dispersions B1), the amount of carboxy-functional monomers is between 0.8 and 5 wt.%, in particular between 1.2 and 4 wt.%, and the amount of hydroxy-functional monomers is between 1 and 45 wt.%, preferably between 6 and 30 wt.%.

[0159] The secondary polyacrylate dispersions B1) suitable for the formulations according to the invention are prepared from the olefinically unsaturated monomers in the presence of known polymerization initiators. Examples of suitable initiators are peroxy compounds such as diacyl peroxides, alkyl peresters, dialkyl peroxides, peroxydicarbonates, inorganic peroxides, or azo compounds.

[0160] In principle, any organic solvent is suitable for preparing the secondary polyacrylate dispersions B1). These solvents can be used in any amount, but preferably in amounts of less than 20% by weight, based on the total monomers. Preference is given to solvent mixtures consisting of at least one hydrophobic solvent such as solvent naphtha, toluene, xylene, or crystal oil, and at least one hydrophilic solvent such as butyl glycol, butyl diglycol, diethylene glycol, propylene glycol monomethyl ether, or dipropylene glycol monomethyl ether.

[0161] The potentially ionic groups incorporated into the copolymer, especially carboxyl groups, are usually neutralized with suitable tertiary amines. Examples of suitable neutralizing amines are tertiary monoamines such as trimethylamine, triethylamine, tripropylamine, tributylamine, ethyldiisopropylamine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N-methylpiperidine, N-ethylpiperidine; tertiary diamines such as 1,3-bis(dimethylamino)propane, 1,4-bis(dimethylamino)butane, or N,N'-dimethylpiperazine; or tertiary amines bearing isocyanate-reactive groups, for example, alkanolamines such as dimethylethanolamine, methyldiethanolamine, 2-aminomethyl-2-methylpropanol, or triethanolamine.

[0162] The secondary polyacrylate dispersions B1) can be prepared by any known prior art processes, for example in a feed process, batch process or cascade process.

[0163] After the copolymer solution has been dispersed in water, the solvent used can be removed proportionally or completely by distillation.

[0164] The pH of the secondary polyacrylate dispersions B1) suitable for the coating compositions according to the invention is preferably from 5 to 11, particularly preferably from 6 to 10.

[0165] The solids contents of the secondary polyacrylate dispersions B1) are preferably 20 to 60 wt.%, particularly preferably 35 to 55 wt.%. The average particle sizes are generally 20 to 400 nm.

[0166] In the production of secondary polyacrylate dispersions, reactive diluents, as they are called, can be used either instead of or together with the solvents. Suitable reactive diluents include, for example, room-temperature-liquid polyethers with a functionality of two or three, low-viscosity polyesters such as reaction products of 1 mol of a dicarboxylic acid, such as dimer fatty acids or adipic acid, with 2 mol of a diol or triol, or with 2 mol of the glycidyl ester of versatic acid. Examples of other suitable reactive diluents include reaction products of ε-caprolactone with low-molecular-weight alcohols and hydroxy-functional oils such as castor oil.

[0167] Suitable aqueous polymer dispersions B) for the coating agents according to the invention are, for example, so-called hydroxy-functional primary polyacrylate dispersions B2), which can be prepared in a conventional manner by copolymerizing olefinically unsaturated monomers having hydroxyl groups with hydroxyl-free olefinic monomers directly in aqueous emulsion in the presence of suitable surface-active substances.

[0168] Suitable primary polyacrylate dispersions B2) and their preparation are described, for example, in RO Athey Jr., Emulsion Polymer Technology, Dekker, New York, 1991.

[0169] Monomers suitable for the preparation of such primary polyacrylate dispersions B2) basically include the monomers already mentioned above in connection with the preparation of the secondary polyacrylate dispersions B1.

[0170] In emulsion polymerization, the polymerization initiators are usually either initially introduced and / or added in parallel, optionally with the addition of feed and / or replenishment. Examples of suitable initiators are redox systems, peroxides, persulfates, and / or azo compounds such as dibenzoyl peroxide, dicumene peroxide, cumene hydroperoxide, potassium peroxodisulfate, ammonium peroxodisulfate, azobisisobutyronitrile, or di-tert-butyl peroxide.

[0171] Also suitable as aqueous polymer dispersions B) for the coating compositions according to the invention are the known hybrid forms of polyacrylate dispersions, such as polyester-polyacrylate dispersions B3). These dispersions contain both polyacrylate segments and polyester segments and are obtained, for example, by radical (co)polymerization of monomers of the type mentioned above in connection with the preparation of secondary polyacrylate dispersions B1) in the presence of a polyester component, a reaction that can be carried out in bulk or, preferably, in organic solution. Suitable polyester components are described below as possible synthesis components for the preparation of the polyurethane dispersions B4).

[0172] Polyester-polyacrylate dispersions B3) suitable as aqueous polymer dispersions B) preferably contain a polyester content of 10 to 75 wt.%, particularly preferably 20 to 60 wt.%, based on the total solids content of the dispersion.

[0173] Polyurethane dispersions B4) are also suitable as aqueous polymer dispersions B) for the coating compositions according to the invention. These dispersions are the known, generally self-emulsifying polyurethanes or polyurethane-polyureas in aqueous form.

[0174] Self-emulsifying polyurethanes contain ionic and / or non-ionic hydrophilic groups in the polymer chain, whereby these groups can be incorporated either directly into the polymer chain or in a pendant or terminal position.

[0175] Suitable polyurethane dispersions B4) can be obtained by methods known to the person skilled in the art by preparing a polyurethane or a polyurethane prepolymer in the melt or in organic solution and subsequently dispersing it therein in water, wherein, if appropriate, a chain extension reaction for increasing the molecular weight can be carried out in organic solution parallel to the dispersing step or after the dispersing step.

[0176] In the preparation of suitable polyurethane dispersions B4), the incorporation of hydrophilic groups into the polyurethane can be carried out using various compounds which are reactive towards isocyanate groups and which are potentially ionic and / or non-ionic, for example by incorporating hydroxycarboxylic acids such as dimethyloleacetic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylbutyric acid, 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, hydroxypivalic acid or mixtures of such acids, aminocarboxylic acids such as the Michael adducts of isophoronediamine or ethylenediamine with acrylic acid, aminosulfonic acids such as aminoethylethanesulfonic acid, hydroxy- or amino-functional phosphonic acids and / or mono-, di- or trifunctional polyethylene oxide units in the molecular weight range 350 to 2500 g / mol. The use of mixtures of such compounds is also possible.

[0177] Particularly suitable hydrophilic units are dimethylolpropionic acid, dimethylolbutyric acid, mono- or dihydroxyfunctional polyethylene oxide units of the molecular weight range specified above, as well as hydroxyfunctional or aminofunctional sulfonic acids and / or sulfonates.

[0178] Tertiary amines and / or tertiary amino alcohols, as described above as neutralizing amines for suitable secondary polyacrylate dispersions B1), are preferably used as neutralizing agents for these hydrophilic units.

[0179] To produce suitable polyurethane dispersions B4), any aliphatic, cycloaliphatic, araliphatic and / or aromatic di- and / or polyisocyanates are used, such as those already mentioned above as starting compounds.

[0180] The use of isophorone diisocyanate, 4,4'-diisocyanatodicyclohexylmethane and / or hexamethylene diisocyanate is preferred.

[0181] Further synthesis components for the preparation of suitable polyurethane dispersions B4) are polyester, polyesteramide, polyacetal, polyether, polysiloxane and / or polycarbonate polyols in the molecular weight range 500 to 18,000 g / mol with a functionality of 1 to 5, preferably 2 to 2.5.

[0182] Suitable polyester polyols for preparing the polyurethane dispersions B4) are, for example, those having an average functionality of 1.5 to 5, as can be prepared in a known manner by reacting aliphatic compounds, cycloaliphatic or aromatic dicarboxylic acids and / or polycarboxylic acids and / or their anhydrides, such as succinic acid, glutaric acid, adipic acid, sebacic acid, pimelic acid, subinic acid, azelaic acid, nonanedicarboxylic acid, decanedicarboxylic acid, phthalic acid, isophthalic acid B.Hexahydrophthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic acid, maleic acid, maleic anhydride, fumaric acid, dimer and trimer fatty acids, dimethyl terephthalate and bisglycol terephthalate, with polyhydric alcohols such as 1,2-ethanediol, 1,2- and 1,3-propanediol, the isomeric butanediol, pentanediol, hexanediol, heptanediol and octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2- and 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol-4,4'-(1-methylethylidene)biscyclohexanol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, 1,2,3-propanetriol, 1,1,1-trimethylolethane, 1,2,6-hexanetriol, 1,1,1-trimethylolpropane, 2,2-bis(hydroxymethyl)-1,3-propanediol and / or 1,3,5-tris(2-hydroxyethyl)isocyanurate.

[0183] Suitable polyester polyols include those that can be prepared in the usual way from lactones and individual polyhydric alcohols, as listed above as ring-opening starter molecules. Examples of suitable lactones for the preparation of these polyester polyols are beta-propiolactone, gamma-butyrolactone, gamma- and delta-valerolactone, ε-caprolactone, 3,5,5- and 3,3,5-trimethylcaprolactone, or any mixtures of such lactones.

[0184] Suitable polycarbonate polyols for producing the polyurethane dispersions B4) are, in particular, the known reaction products of dihydric alcohols, such as those mentioned above in the list of polyhydric alcohols, with diaryl carbonates, such as, for example, diphenyl carbonate, dimethyl carbonate, or phosgene. Other suitable polycarbonate polyols are those which, in addition to carbonate structures, also contain ester groups. These are, in particular, the known polyester carbonate diols, such as those obtainable, for example, according to the teaching of DE-B 1 770 245 by reacting dihydric alcohols with lactones, such as, in particular, ε-caprolactone, and subsequently reacting the resulting polyester diols with diphenyl or dimethyl carbonate. Also suitable are polycarbonate polyols which, in addition to carbonate structures, contain ether groups.These are in particular the polyether carbonate polyols known per se, as are obtainable, for example, by the method of EP-A 2046861 by catalytic conversion of alkylene oxides and carbon dioxide in the presence of H-functional starter molecules.

[0185] Suitable polyether polyols for preparing the polyurethane dispersions B4) are, for example, those obtainable in a conventional manner by alkoxylation of suitable starter molecules. For the preparation of these polyether polyols, any polyhydric alcohols, for example those from the molecular weight range of 62 to 400, of the type described above with regard to the preparation of polyester polyols, can be used as starter molecules. Alkylene oxides suitable for the alkoxylation reaction are, in particular, ethylene oxide and propylene oxide, which can be used in any order or as a mixture in the alkoxylation reaction. Other suitable polyether polyols are polytetramethylene ether glycols, which are prepared, for example, according to Angew. Chem. 72, 927 (1960) by polymerizing tetrahydrofuran and which have number-average molecular weights of 400 g / mol to 4000 g / mol.

[0186] To produce suitable polyurethane dispersions B4), block copolymers based on the polyols mentioned can also be used, for example polyether-polyester copolymers, polycarbonate-polyester copolymers or polycarbonate / polyether copolymers.

[0187] Preferred polyols for the preparation of suitable polyurethane dispersions B4) are polyester polyols, polycarbonate polyols and / or C3 and / or C4 polyether polyols.

[0188] When preparing suitable polyurethane dispersions B4), low-molecular-weight alcohols with a functionality of 2 to 4 can also be used if necessary. These are, in particular, compounds with a molecular weight of 500 g / mol, for example the simple polyhydric alcohols of the type mentioned above as synthesis components for polyester polyols or amino alcohols such as diethanolamine, ethanolamine, diisopropanolamine, propanolamine, which may optionally also be present in ethoxylated and / or propoxylated form, as well as any mixtures of such alcohols.

[0189] In the production of suitable polyurethane dispersions B4), compounds known as chain extenders are generally used. These chain extenders are, in particular, diamines, polyamines, and / or amino alcohols such as diethanolamine, 1,2-diaminopropane, 1,4-diaminobutane, 2,5-diamino-2,5-dimethylhexane, 1,5-diamino-2-methylpentane, 1,6-diaminohexane, 2,2,4- and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, triaminononane, ethylenediamine, isophoronediamine, diethylenetriamine, hydrazine, adipine dihydrazide, hydroxyethylethylenediamine, bishydroxyethylethylenediamine, aminopropanol, aminoalkoxysilanes, and any mixtures of such compounds.

[0190] Suitable polyurethane dispersions (B4) can be prepared using suitable solvents. Examples of suitable solvents are acetone, methyl ethyl ketone, N-methylpyrrolidone, and / or N-ethylpyrrolidone.

[0191] Suitable polyurethane dispersions B4) can be prepared to accelerate the reaction or to achieve special effects, also using catalysts commonly used in polyurethane chemistry such as dibutyltin dilaurate, dibutyltin oxide, tin dioctoate, tin chloride and / or tertiary amines.

[0192] Typically, in the preparation of polyurethane dispersions in melt or organic solution, diisocyanates and / or polyisocyanates are reacted with polyols and hydrophilic units of the type mentioned to form an isocyanate-functional prepolymer, which is then further reacted either in the melt, in organic solution or in aqueous dispersion, with a chain extender of the type mentioned to form a high molecular weight polyurethane which is dispersible and / or dispersed in water.

[0193] Any solvent used can be completely or partially distilled off after dispersion.

[0194] Suitable polyurethane dispersions B4) for the coating compositions according to the invention preferably have solids contents of 25 to 60 wt.%, pH values ​​of 5.5 to 11 and / or average particle sizes of 20 to 500 nm.

[0195] Further suitable aqueous polymer dispersions B) for the formulations according to the invention are polyester dispersions and polyester solutions B5), as obtained by dispersing suitable water-dilutable polyester polyols in water.

[0196] Examples of suitable water-dilutable polyester polyols are the dispersing resins known, for example, from paint technology, which have very good pigment wetting and / or pigment affinity qualities and have acid numbers in the range of 25 to 75 mg KOH / g, hydroxyl group contents of 2.5 to 10 wt.%, molecular weights in the range of 750 to 5000 g / mol and / or fatty acid components in amounts of 15 to 50 wt.%.

[0197] Suitable polyester dispersions and solutions B5) for the formulations according to the invention are obtained, for example, by reacting polyester polyols, for example as described above as synthesis components for the preparation of polyurethane dispersions B4) with acid anhydrides such as phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic anhydride, trimellitic anhydride, or pyromellitic anhydride. The reaction is carried out, for example, such that the acid anhydrides react with some of the hydroxyl groups, causing ring opening of the anhydride and incorporation into the polyester. In this way, hydroxy-functional and simultaneously carboxy-functional polyesters are obtained, which, after complete or proportional neutralization of the carboxyl groups, can be dissolved or dispersed in water. Aqueous polyester dispersions or solutions B5) with average particle sizes of 10 to 200, preferably 25 to 100 nm are obtained.

[0198] Generally speaking, the aqueous polymer dispersions B) used in the coating compositions according to the invention are dispersions of the type mentioned that are hydroxy- and / or amino-functional. However, the use of non-functional polymer dispersions B) as binder components in the coating compositions according to the invention is also possible.

[0199] The aqueous polymer dispersion B) used in the coating compositions according to the invention preferably contains at least one aqueous secondary polyacrylate dispersion B1), a polyester-polyacrylate dispersion B3) based on polyester polyols, polycarbonate polyols and / or C 3 or C 4 polyether polyols.

[0200] Preference is given to using hydroxy-functional aqueous polymer dispersions B) in the coating compositions according to the invention which, based on resin solids, have a hydroxyl group content of 0.5 to 7.0% by weight, preferably 0.5 to 6.0% by weight, particularly preferably 1.0 to 5.0% by weight, acid numbers of less than 50 mg KOH / g, preferably less than 40 mg KOH / g, particularly preferably less than 30 mg KOH / g and / or number-average molecular weights Mn, as determined by gel permeation chromatography, of 500 to 30,000 g / mol, preferably 1,000 to 15,000 g / mol, particularly preferably 1,500 to 10,000 g / mol.

[0201] In the embodiment according to the invention in which an aqueous two-component formulation is present, at least one emulsifier can also be present in component B. Suitable external and internal emulsifiers are known per se to the person skilled in the art and are described, for example, in "Polyurethanes - Coatings, Adhesives and Sealants", 2019, Meier-Westhues, Danielmeier, Kruppa, Squiller, Vincentz Network GmbH, pp. 48-51. Particularly suitable emulsifiers contain either functional groups that can be converted into cations by neutralizing agents and / or quaternizing agents, and / or cationic groups, or functional groups that can be converted into anions by neutralizing agents, and / or anionic groups, and / or nonionic hydrophilic groups.

[0202] Furthermore, the present invention relates to the use of the NCO-terminated polysiloxane prepolymer according to the invention as a curing agent in a coating formulation. The same applies to the amounts and other components present in the two-component formulation according to the invention. Examples

[0203] Unless otherwise stated, all experiments were conducted at 23 °C and 50% relative humidity.

[0204] The NCO content was determined titrimetrically according to DIN EN ISO 11909:2007-05.

[0205] OH numbers were determined titrimetrically according to DIN 53240-2:2007-11.

[0206] Acid numbers were determined according to DIN EN ISO 2114:2002-06.

[0207] The stated OH contents were calculated from the analytically determined OH numbers. The stated values ​​refer to the total weight of the respective composition, including any solvents used.

[0208] The residual monomer contents were measured by gas chromatography with an internal standard according to DIN EN ISO 10283:2007-11.

[0209] The solid content was determined according to DIN EN ISO 3251:2008-06.

[0210] The drying times (T1, T3 and T4) were determined according to DIN EN ISO 9117-5:2010-07, Drying test Part 5: Modified Bandow-Wolff method.

[0211] The viscosity was determined at 23 °C according to DIN EN ISO 3219 / A:1994-10. Unless otherwise stated, the viscosity is dynamic.

[0212] The number-average molecular weight Mn is determined by gel permeation chromatography (GPC) in tetrahydrofuran at 23 °C. The procedure is according to DIN 55672-1:2016-03: "Gel Permeation Chromatography, Part 1 - Tetrahydrofuran as Eluent" (SECurity GPC system from PSS Polymer Service, flow rate 0.6 ml / min; columns: 2×PSS SDV (100A), 2×PSS SDV (50A), 8×300 mm, 5 µm; RID detector (RI-Agilent 1260). Polystyrene samples of known molecular weight are used for calibration. The calculation of the number-average molecular weight is software-supported.

[0213] The gloss at 20° of the resulting coatings was determined reflectometrically according to DIN EN ISO 2813:2015-02.

[0214] The condensate test was carried out according to DIN EN ISO 6270-2 CH:2018-04.

[0215] The contact angle was determined according to DIN 55660-2:2011-12. For each value, 10 points on the plate were examined for contact angles with water, and the mean value of these measurements is reported.

[0216] The wet scratch resistance of the coatings was tested using a laboratory washing system according to DIN EN ISO 20566:2013-06. The gloss loss is expressed in Gloss Units (GU) after scratching (10 cycles). The lower the gloss loss in GU, the more resistant the coating is to wet scratching.

[0217] Resistance to dry scratching was tested using a linear stroke device (crockmeter) in accordance with DIN 55654:2015-08. A weight (950 g), covered on its flat underside with polishing paper (3M, Grade: 9 MIC), was placed on the coating without scratching the coating and then mechanically moved in a track over the coating. Ten or 20 double strokes were performed. After exposure to the scratching medium, the test surface was cleaned with a soft cloth, and the gloss was then measured at three different locations perpendicular to the scratching direction. The lower the gloss loss GU calculated from the mean value of this measurement, the more resistant the coating to scratching.

[0218] The determination of pendulum damping according to König was carried out according to DIN EN ISO 1522:2007-04 on glass plates.

[0219] The coatings described were applied by spraying. The dry film thickness for all films was 35 to 40 µm.

[0220] Solvent and water resistance were determined according to DIN EN ISO 4628-1:2016-07. For the solvent resistance test, the solvents used were xylene, also abbreviated as "Xy," methoxypropyl acetate (MPA), ethyl acetate (EA), and acetone (Ac). The contact time was 5 minutes in each case. For the water resistance test, the contact time was 24 hours in each case. Sampling was carried out according to the specified standard. The test surface is assessed visually and by scratching, with the following classification: 0 = No detectable change; 1 = Swelling ring, hard surface, only visible change; 2 = Swelling ring, slight softening; 3 = Significant softening (possibly slight blistering); 4 = Severe softening (possibly severe blistering), scratchable down to the substrate; 5 = Coating completely destroyed without external influence.

[0221] Reflow describes the recovery of a scratched coating surface after exposure to heat, based on its gloss value. A coating is scratched using wet or dry scratching. The residual gloss was determined after the scratching cycle. The coating was placed in an oven at 60 °C for 2 hours, and the gloss was then determined using the previously described method. Reflow is expressed as a percentage, i.e., the ratio of residual gloss to reflow value.

[0222] The contact angle was determined according to DIN 55660-2:2011-12.

[0223] The following reagents were used in the examples and comparative examples: Diisocyanates:

[0224] 1,6-Hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI) were purchased from Covestro and used without purification. Polyols:

[0225] Polyol 1 is based on a polyetherdiol (Dianol®< 320 HP, solid) containing secondary OH groups and a hydroxyl value of 325 mgKOH / g. Reaction with propylene oxide yields polyol 1 with a molecular weight of 550 g / mol.

[0226] Polyol 2 is a polyester polyol composed of hexanediol, butanediol, adipic acid and propanediol with a functionality of 2, a molecular weight of approximately 400 g / mol and an OH content of approximately 8 wt and a viscosity of 800 mPa s

[0227] Polyol 3 is a polyacrylate polyol composed of methyl methacrylate, acrylic acid, styrene, and hydroxyethyl methacrylate with an OH content of 2.8 wt.% based on the solids, dissolved in butyl acetate with a solids content of 75 wt.%. The viscosity is 5000 mPa s.

[0228] Polyol 4 is an α,ω-hydroxypropyl-terminated polydimethylsiloxane (Baysilone OF OH 702 (4 wt%)) with an OH content of 4 wt% and a molecular weight of 600 to 800 g / mol. The clear liquid has a kinematic viscosity of 37 mm 2 < ·s -1 <

[0229] Polyol 5 is an aliphatic, hydroxyfunctional polycarbonate polyester polyurethane dispersion. It was purchased from Covestro and has the following characteristics: Viscosity: 300-1500 mPa s Non-volatile content: 50.0-54.0% OH content: approx. 1%

[0230] Polyol 6 is a polyester polyacrylate dispersion. It was purchased from Covestro and has the following characteristics: Viscosity: 700-7,200 mPa s Non-volatile content: 41-43% OH content: 3,8%

[0231] Polyol 7 is a polyacrylate polyol. It was purchased from Allnex and is sold under the trade name Setalux DA 870 BA. It has the following characteristics: Viscosity: 3500 mPa.s Non-volatile content: 70% OH content: 4.2% (on solids)

[0232] Amine 1 is a secondary amine prepared from 4,4'-methylenebis(cyclohexylamine) and diethyl maleate and has the following characteristics: Amine number: 200 mg KOH / g Viscosity (25 °C): 900-2,000 mPa s Color number (Hazen): ≤ 250

[0233] TMP stands for 1,1,1-trimethylolpropane, a trifunctional polyol with a molecular weight of 134 g / mol. Polyisocyanates:

[0234] Polyisocyanate 1 is a trimer of 1,6-hexamethylene diisocyanate with a functionality of 2.8 to 3.6, an NCO content of 23 wt.%, an equivalent weight of 183 g / mol and a viscosity of 1200 mPa s

[0235] Polyisocyanate 2 is a trimer of 1,6-hexamethylene diisocyanate with a functionality of 2.8 to 3.6, an NCO content of 21.8 wt.%, a viscosity of 3000 mPa·s and an equivalent weight of 193 g / mol.

[0236] Polyisocyanate 3 is an allophanate based on 1,6-hexamethylene diisocyanate and propanol / butanol with a functionality of 2.0 to 2.8, an equivalent weight of 215 g / mol and a viscosity of 500 mPa s.

[0237] Polyisocyanate 4 is a trimer of isophorone diisocyanate with a functionality of 2.8 to 3.6, an NCO content of 11.9%, a solids content of 70%, Solvent Naptha 100 (30 wt%), an equivalent weight of 360 g / mol and a viscosity of 1,600 mPa·s and.

[0238] Polyisocyanate 5 is an ionically hydrophilized polyisocyanate based on an HDI trimer and a sulfonate-based hydrophilizing agent, with a functionality of ≤ 2.8, an NCO content of 20.3 wt% and a viscosity of 3500 mPa·s. Additives and catalysts:

[0239] Tinuvin 292, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (509 g / mol) and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (370 g / mol), is a light stabilizer based on a sterically hindered amine. Its viscosity is 400 mPa s. The product was purchased from BASF and used without further purification.

[0240] Tinuvin 1130, a mixture of β-[3-(2-H-benzotriazol-2-yl)-4-hydroxy-5-tert-butylphenyl]-propionic acid poly(ethylene glycol) 300 ester (637 g / mol) and bis{b-[3-(2-H-benzotriazole-2-yl)-4-hydroxy-5-tert-butylphenyl]-propionic acid poly(ethylene glycol) 300 ester (975 g / mol), is a UV absorber. The viscosity is 7400 mPa s. The product was purchased from BASF and used without further purification.

[0241] BYK ®< 141 (as delivered solids: 96.8%), BYK ®< 331 (as delivered solids: 100%), and BYK ®< 348 (as delivered solids: 100%) are silicone-containing flow agents composed of a covalently bonded siloxane and a polyether. These products were purchased from BYK.

[0242] Addocat®< 201 is a standard catalyst based on dibutyltin dilaurate (DBTL), used at a concentration of 0.03 wt.% on a solid binder. The catalyst was purchased from Lanxess.

[0243] Lucrafoam®< DNE 01 is a mineral oil-based defoamer used in all pH ranges. The defoamer was purchased from Levaco Chemicals.

[0244] Tego ®< -Wet KL 245 is a siloxane-based wetting agent with an active content of 100%. It was purchased from Evonik Industries.

[0245] Aquacer 513 is a VOC-free wax emulsion based on HDPE for improving surface protection in aqueous media. The wax emulsion was purchased from BYK.

[0246] Decosoft Transparent ®< 7 D are highly cross-linked aliphatic polyurethane particles (100%) that impart a soft-feel effect and a matte finish to the coating. This product was purchased from Microchem.

[0247] Matting agent Acematt ®< 3300 ACEMATT 3300 is a fumed silica post-treated with a special polymer. This matting agent is characterized by maximum matting efficiency and high transparency.

[0248] Solvents such as butyl acetate (BA) and methoxypropyl acetate (MPA) were purchased from Azelis. Example 1 (according to the invention)

[0249] 441 g of HDI were initially charged and heated to 105 °C. After adding 280 g of Baysilon OFOH 702, the reaction mixture was stirred for 3 h at 100 °C under a nitrogen atmosphere. After stirring for 2 h at 110 °C, the unreacted monomeric HDI was separated in a thin-film evaporator at a temperature of 150 °C and a pressure of 0.1 mbar. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained. NCO content: 6.65 wt% Solid content: 100% viscosity 320 mPa s HDI: < 0.3 wt% Example 2 (according to the invention)

[0250] 583 g of IDPI were initially charged and heated to 105 °C. After adding 280 g of Baysilon OFOH 102, the reaction mixture was stirred for 3 h at 100 °C under a nitrogen atmosphere. After stirring for 2 h at 110 °C, the unreacted monomeric HDI was separated in a thin-film evaporator at a temperature of 150 °C and a pressure of 0.1 mbar. A virtually colorless, clear NCO-terminated prepolymer (425 g) with the following characteristics was obtained. NCO content: 7.35 wt% Solid content: 100% viscosity 3.500 IPDI: < 0.3 wt% Example 3 (comparative example, one-pot reaction)

[0251] 756 g of Desmodur H were initially charged and heated to 105 °C. A mixture of 8 g of TMP, 33 g of Polyol 1, and 120 g of Polyol 4 was then added, and the reaction mixture was stirred for 2 h at 110 °C under a nitrogen atmosphere. After stirring for 2 h at 110 °C, the unreacted monomeric HDI was separated in a thin-film evaporator at a temperature of 130 °C and a pressure of 0.1 mbar. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained. NCO content: 9,5% Solid content: 100% viscosity 960 mPa s Example 4 (according to the invention)

[0252] 30.5 g of the product from Example 1 were dissolved with 21.3 g of Polyol 2, 50% w / w in MPA, and reacted in the presence of Addocat 201 (0.03 w / w). The reaction was carried out at 60 °C under a nitrogen atmosphere. After an NCO content of less than 0.1 w / w was measured, 55.5 g of Desmodur N3600 were added, and the reaction mixture was adjusted to a solids content of 50 w / w with MPA. The reaction was carried out at 60 °C until an NCO content of 4.9 w / w was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained. NCO content: 4,9% Solid content: 50% viscosity 190 mPa s Example 5 (according to the invention)

[0253] 15.25 g of the product from Example 1 were reacted with 3.35 g of 1,1,1-trimethylolpropane, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 82.5 g of Polyisocyanate 3 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 6.8 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained. NCO content: 6.75 wt% Solid content: 50 wt.% viscosity 232 mPa s Example 6 (according to the invention)

[0254] 15.3 g of the product from Example 1 were reacted with 3.35 g of 1,1,1-trimethylolpropane, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 92.5 g of Polyisocyanate 1 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 8.5 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 8.5 wt.% Solid content: 50 wt.% viscosity 110 mPa s Example 7 (according to the invention)

[0255] 5.28 g of the product from Example 2 were reacted with 1.08 g of 1,1,1-trimethylolpropane, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 29.3 g of Polyisocyanate 1 were added. The reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 8.48 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 8.48 wt.% Solid content: 50 wt.% viscosity 175 mPa s Example 8 (according to the invention)

[0256] 5.28 g of the product from Example 2 were reacted with 1.08 g of 1,1,1-trimethylolpropane, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 32.8 g of Polyisocyanate 5 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 6.75 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 6.75 wt.-& Solid content: 50 wt.% viscosity 145 mPa s Example 9 (according to the invention)

[0257] 11.02 g of the product from Example 2 were reacted with 2.24 g of 1,1,1-trimethylolpropane, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 120 g of Polyisocyanate 4 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 6.48 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 6.48 wt% Solid content: 50 wt.% viscosity 180 mPa s Example 10 (according to the invention)

[0258] 11.02 g of the product from Example 2 were reacted with 108 g of Polyol 2, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 120 g of Polyisocyanate 4 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 5.71 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 5.71 wt% Solid content: 50 wt.% viscosity 30 mPa s Example 11 (according to the invention)

[0259] 11.02 g of the product from Example 2 were reacted with 40.5 g of Polyol 3, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 120 g of Polyisocyanate 4 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 5.96% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 5.96 wt% Solid content: 50 wt.% viscosity 160 mPa s Example 12 (according to the invention)

[0260] 6.76 g of the product from Example 1 were reacted with 1.49 g of 1,1,1-trimethylolpropane, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 44.9 g of Polyisocyanate 5 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 7.82 wt.% was reached. A virtually colorless, clear, NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 7.82 wt.% Solid content: 50.0 wt.% viscosity 115 mPa s Example 13 (according to the invention)

[0261] 6.76 g of the product from Example 1 were reacted with 27.0 g of Polyol 3 BA, dissolved in MPA at 50 wt.%, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 44.9 g of Polyisocyanate 5 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 5.84 wt.% was reached. A virtually colorless, clear, NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 5.84 wt% Solid content: 50 wt.% viscosity 100 mPa s Example 14 (according to the invention)

[0262] 6.76 g of the product from Example 1 were reacted with 7.17 g of polyol 2 g (50 wt.%) in MPA in the presence of Addocat 201. After an NCO content of less than 0.1 wt.% was measured, 44.9 g of polyisocyanate 5 (0.03 wt.%) were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 7.14 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 7.14 wt% Solid content: 50 wt.% viscosity 70 mPa s Example 15 (according to the invention)

[0263] 6.09 g of the product from Example 1 were reacted with 24.3 g of polyisocyanate 3 (50 wt.%) in MPA in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 38.6 g of polyisocyanate 2 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 6.75 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 6.75 wt% Solid content: 50 wt.% viscosity 110 mPa s Example 16 (according to the invention)

[0264] 6.09 g of the product from Example 1 were reacted with 1.34 g of 1,1,1-trimethylolpropane, 50 wt.% in MPA, in the presence of Addocat 201 (0.03 wt.%). After an NCO content of less than 0.1 wt.% was measured, 38.6 g of Polyisocyanate 2 were added, and the reaction mixture was adjusted to a solids content of 50 wt.% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 6.75 wt.% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 6.75 wt% Solid content: 50 wt% viscosity 200 mPa s Example 17 (according to the invention)

[0265] 6.09 g of the product from Example 1 were reacted with 6.45 g of Polyol 2 in 50 wt% MPA in the presence of Addocat 201 (0.03 wt%). After an NCO content of less than 0.1 wt% was measured, 38.6 g of Polyisocyanate 2 were added, and the reaction mixture was adjusted to a solids content of 50 wt% with MPA. The reaction took place with stirring at 60 °C until an NCO content of 6.75 wt% was reached. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 6.75 wt% Solid content: 50 wt.% viscosity 90 mPa s Example 17 (according to the invention)

[0266] 12.63 g of the product from Example 1 was mixed with 16.56 g of Amine 1 and stirred at RT for 8 h. Subsequently, 77.20 g of Polyisocyanate 2 were added and stirred at RT for 8 h. A virtually colorless, clear NCO-terminated prepolymer with the following characteristics was obtained: NCO content: 7.01 (wt.%) Solid content: 50 wt.% viscosity 100 mPa s Application examples:

[0267] Table 1 shows various coating systems. The components of the coating formulations were mixed together and applied to glass and basecoat using a spray application method (multi-layer system). The coated specimens were dried for 30 minutes at 60 °C. Table 1.

[0268] Table 1: The formulations were sprayed and baked at 60 °C for 30 min. All analytical values ​​were determined after 7 days. Lacquer 1 Lacquer 2 Lacquer 3 Lacquer 4 Lacquer 5 Lacquer 6 Lacquer 7 (cf.) Lacquer 8 (cf.) Lacquer 9 (cf.) product Solids content [%] Sample weight [g] Sample weight [g] Sample weight [g] Sample weight [g] Sample weight [g] Sample weight [g] Sample weight [g] Sample weight [g] Sample weight [g] Polyol 7 70 48,33 48,33 47,96 47,96 48,37 48,37 49,21 49,21 47,82 Byk 141 96,8 0,25 - 0,25 - 0,25 - 0,25 - 0,25 Byk 331 10 1,50 - 1,50 - 1,50 - 1,50 - 1,50 Tinuvin 292 50 1,00 1,00 1,00 1,00 1,00 1,00 1,00 1,00 1,00 Tinuvin 1130 50 2,00 2,00 2,00 2,00 2,00 2,00 2,00 2,00 2,00 Addocat 201 1 1,50 1,50 1,50 1,50 1,50 1,50 1,50 1,50 1,5 Butyl acetate 0 10,60 10,60 10,09 10,09 9,95 9,95 11,08 11,08 11,23 MPA 0 6,44 6,44 6,15 6,15 6,06 6,06 6,74 6,74 6,86 xylene 0 10,60 10,60 10,09 10,09 9,95 9,95 11,08 11,08 11,23 Example 3 50 - - - - - - - - 2,39 Example 4 50 3,07 3,07 - - - - - - Example 5 50 - - 5,91 5,91 - - - - Example 6 50 - - - - 6,39 6,39 - - Polyisocyanate 1 100 14,71 14,71 13,55 13,55 13,03 13,03 15,63 15,63 14,11 Cf. = comparative example

[0269] For the various coating formulations, the contact angle against H2O was determined after spray application. For coating 1 (with leveling agent) compared to coating 2 (without leveling agent), it is demonstrated here by way of example that the silicone-containing leveling agents used have no influence on the contact angle, as the values ​​are within the same range (97° and 100°, respectively) and are therefore comparable. For coatings 1 to 5, it was shown that the addition of NCO-terminated prepolymers containing siloxane chains can increase the contact angle without affecting common coating parameters such as gloss.

[0270] Furthermore, only a slight fluctuation in the contact angle was observed after dry scratching and, surprisingly, in the condensation test (SWT). The results differ significantly from the comparisons Paint 8 and Paint 9, which do not contain NCO-terminated, siloxane-containing prepolymers; they exhibit a contact angle that is approximately 20° lower. Comparative Paint 9 also contains siloxane-terminated prepolymer, but with a different composition. As a result, a decrease in the contact angle was observed in the condensation test. Table 2: Determination of the contact angle of different clear coats before and after exposure to scratching and condensation water test (SWT). Contact angle H 2 O [°] Paint 1 [1]< Lacquer 2 Lacquer 3 [1]< Lacquer 5 [1]< Lacquer 7 [1]< (cf.) Lacquer 8 (cf.) Lacquer 9 (cf.) Basecoat (before) 97 100 96 96 83 80 101 After PP and reflow (2h 60°C) 94 93 95 94 82 80 - According to SWT [2]< 97 95 96 95 73 74 91 [3]< Δ 0 5 0 3 30 6 10 [1] With leveling agent. [2] SWT = Condensation test.

[0271] Surprisingly, it was observed that the siloxane-containing coatings exhibited better reflow than the comparative examples. This will be illustrated using Coating 3 as an example compared to Coating 7. After dry scratching, the gloss drops to approximately 11 gloss units for both clear coats—from the same initial value. After reflow, a value of 87 gloss units is obtained for Coating 3, whereas only 77 gloss units are observed for Coating 7. Table 3: Dry scratching using a hammer for various coating systems. Reflow: 2 hours, 60 °C. All coating systems contain leveling agents. Dry scratching with a hammer Lacquer 1 Lacquer 3 Lacquer 5 Lacquer 7 Lacquer 9 Shine 20° before 91,1 91,1 91,4 91,4 89,6 Shine 20° after 11,2 11,5 11,5 11,0 9,9 Residual gloss after PP [%] 12,3 12,6 12,6 12,0 11,0 Gloss 20° Reflow 86,1 87,3 85,8 70,4 77.3 Residual gloss after reflow [%] 94,5 95,8 93,9 77,0 86.3

[0272] Table 4 compares coating systems containing all flow control additives. Here, too, it is clearly evident that the siloxane-containing systems exhibit significantly better residual gloss and reflow (e.g., Coating 6 vs. Coating 8). Table 4: Dry scratch resistance measured using a crockmeter for various coating systems. Reflow: 2 hours, 60 °C. All coating systems contain no flow agents. Dry scratching using a crockmeter Lacquer 2 Lacquer 4 Lacquer 6 Lacquer 8 Shine 20° before 91 91 91 92 Shine 20° after 42 34 38 15 Residual gloss after PP [%] 46 37 42 16 Gloss 20° Reflow 81 69 63 29 Residual gloss after reflow [%] 89 76 70 46

[0273] Another surprising, positive effect was observed with the addition of the NCO-terminated siloxane prepolymers regarding improved appearance: The coating of the standard formulation, without leveling additives, develops an orange peel effect on the surface. When the NCO-terminated siloxane prepolymers according to the invention were used and leveling additives were omitted, no orange peel effect was observed. Thus, by adding the NCO-terminated siloxane prepolymers according to the invention, no additives are required for the clearcoat, and at the same time, no orange peel effect is formed.

[0274] Furthermore, the compatibility of the NCO-terminated polysiloxane prepolymers was investigated. This is illustrated by the formulation in Table 5. Table 5: Coating formulations with increased NCO-terminated siloxane content. Lacquer 10 Lacquer 11 Lacquer 12 PIC / NCO-siloxane (solid-on-solid binder) 8:2 7:3 6:4 Polyol 7 50.86 47.54 44.23 Tinuvin 292 1.08 1.04 0.99 Tinuvin 1130 2.16 2.08 1.98 Addocat 201 1.62 1.55 1.38 BA / MPA / XY 33.28 29.27 27.51 Example 4 7.40 11.10 14.80 Polyisocyanate 1 14.80 12.95 11.10 Solids (%) 50% 50% 50%

[0275] As shown in Table 6, the new coating raw materials could be used over a wide concentration range. Table 6: Spray painting of paint 10 and paint 11 Lacquer 10 Lacquer 11 Lacquer 12 Optical properties Clear Clear Clear spray optics Smooth Smooth Smooth Gloss (20 ° / 60 °) 91 / 94 92 / 95 90 / 94 Haze 11 11 10 Solvent resistance Xy-MPA-EA-Ac (5 min.) 2 2 4 4 2 2 4 4 2 2 4 4

[0276] In the following example, the suitability of the new siloxane-containing coating raw materials in water-based coatings was investigated. The corresponding formulations can be found in Table 7. Table 7: 2K water-based paints for soft-feel coatings Lacquer 13 (cf.) Lacquer 14 product Solids content [%] Sample weight [g] Sample weight [g] Polyol 5 52 25 25 Polyol 6 42 31 31 distilled water 0 13,7 13,7 Lucrafoam DNE 01 100 0,2 0,2 Tego-Wet KL 245 50 0,4 0,4 Byk 348 100 0,6 0,6 Aquacer 513 35 1,7 1,7 Decosoft Transparent 7 D 100 7,7 7,7 Matting agent Acematt 3300 100 3,1 3,1 Polyisocyanate 5 100 4,98 4,98 Example 4 50 - 1,87 Polyisocyanate 1 100 11,62 11,62

[0277] In these studies, the standard formulation was kept identical and supplemented with the new, highly compatible NCO-terminated siloxanes. The tests showed that an identical matte coating appearance was achieved. Contact angle measurements showed that the contact angle could be increased from 90° to 110°. Table 8: Water-based paints were applied by spraying, substrate glass. Lacquer 13 (cf.) Lacquer 14 Film optics Matt like varnish 14 Matt like varnish 13 Contact angle H 2 O [°] 89,6 111

Claims

1. NCO-terminated polysiloxane prepolymers of the general formula (I)         [(Q)q]-[(M)m-(P)p-(R)r]t     (I), where R, P, M, Q, r, p, m, q, and t are defined as follows R in each case independently at least one polyisocyanate unit and / or at least one diisocyanate unit, P in each case independently at least one polyol unit, M in each case independently at least one diisocyanate unit and / or at least one polyisocyanate unit, Q at least one polysiloxane unit, r in each case independently a number from 1 to 10, p in each case independently a number from 1 to 10, m in each case independently a number from 1 to 10, q in each case independently a number from 1 to 10, t an integer from 2 to 5, and the units M present are attached directly to the unit Q.

2. Polysiloxane prepolymer according to Claim 1, characterized in that the at least one polyisocyanate unit R is selected from the group consisting of triisocyanates such as 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane or preferably highermolecular-weight oligomers having biuret, uretdione, isocyanurate, iminooxadiazinedione, allophanate, urethane- and / or carbodiimide / uretonimine structural units obtainable through reaction of di- or triisocyanates selected from the group consisting of butane 1,4-diisocyanate, pentane 1,5-diisocyanate (pentamethylene diisocyanate, PDI), hexane 1,6-diisocyanate (hexamethylene diisocyanate, HDI), 4-isocyanatomethyloctane 1,8-diisocyanate (triisocyanatononane, TIN), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), naphthalene 1,5-diisocyanate, diisocyanatodiphenylmethane (2,2'-, 2,4'-, and 4,4'-MDI or mixtures thereof), diisocyanatomethylbenzene (tolylene 2,4- and 2,6-diisocyanate, TDI) and technical mixtures of the two isomers and also 1,3- and / or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3'-dimethylbiphenyl 4,4'-diisocyanate (TODI), 1,4-para-phenylene diisocyanate (PPDI), cyclohexyl diisocyanate (CHDI), and mixtures thereof.

3. Polysiloxane prepolymer according to Claim 1 or 2, characterized in that the at least one polyol unit P is selected from the group consisting of polyether polyols, polyester polyols, polyurethane polyols, polysiloxane polyols, polycarbonate polyols, polybutadiene polyols, polyacrylate polyols, polymethacrylate polyols, copolymers of polyacrylate polyols and polymethacrylate polyols, and mixtures thereof.

4. Polysiloxane prepolymer according to any of Claims 1 to 3, characterized in that M is at least one diisocyanate unit selected from the group consisting of butane 1,4-diisocyanate, pentane 1,5-diisocyanate (pentamethylene diisocyanate, PDI), hexane 1,6-diisocyanate (hexamethylene diisocyanate, HDI), 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), naphthalene 1,5-diisocyanate, diisocyanatodiphenylmethane (2,2'-, 2,4'-, and 4,4'-MDI or mixtures thereof), diisocyanatomethylbenzene (tolylene 2,4- and 2,6-diisocyanate, TDI), and technical mixtures of the two isomers and also 1,3- and / or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3'-dimethylbiphenyl 4,4'-diisocyanate (TODI), 1,4-para-phenylene diisocyanate (PPDI), and also cyclohexyl diisocyanate (CHDI) and mixtures thereof.

5. Polysiloxane prepolymer according to any of Claims 1 to 4, characterized in that the at least one polysiloxane unit Q is derived from a polysiloxane polyol, a polysiloxane polyamine or a polysiloxane polythiol, in particular a polysiloxane polyol.

6. Polysiloxane prepolymer according to any of Claims 1 to 5, characterized in that the at least one polysiloxane unit is present in an amount of from 0.1% to 5% by weight based on the total polysiloxane prepolymer.

7. Polysiloxane prepolymer according to any of Claims 1 to 6, characterized in that the polysiloxane prepolymer has a number-average molecular weight Mn, determined in accordance with the methods stated in the description, of < 4000 g / mol, preferably of > 450 g / mol and < 3000 g / mol, particularly preferably of > 650 g / mol and < 2500 g / mol, and very particularly preferably of > 800 g / mol and < 2500 g / mol.

8. Process for preparing NCO-terminated polysiloxane prepolymer according to any of Claims 1 to 7, comprising at least the following steps: (A) reacting at least one polysiloxane polyol, polysiloxane polyamine and / or polysiloxane polythiol with at least one diisocyanate and / or at least one polyisocyanate so as to obtain at least one NCO-terminated polysiloxane, (B) optionally removing the excess of at least one diisocyanate and / or at least one polyisocyanate, (C) reacting the at least one NCO-terminated polysiloxane from step (A) or (B) with at least one polyol, (D) reacting the product obtained in step (C) with at least one diisocyanate or at least one polyisocyanate so as to obtain the NCO-terminated polysiloxane prepolymer.

9. Process according to Claim 8, characterized in that step (B) is carried out by thin-film evaporation, phase separation, precipitation or combinations thereof.

10. Process according to Claim 8 or 9, characterized in that, after step (B), the content in the reaction mixture of at least one diisocyanate or at least one polyisocyanate, preferably at least one diisocyanate, is not more than 5% by weight, preferably 1% to 0.01% by weight.

11. Formulation comprising at least one NCO-terminated polysiloxane prepolymer according to any of Claims 1 to 7, preferably in an amount of from 5% to 70% by weight based on the entire formulation.

12. Formulation according to Claim 11, characterized in that it is a paint formulation, in particular a 2-component formulation.

13. Use of the NCO-terminated polysiloxane prepolymer according to any of Claims 1 to 7 as a curing agent in a paint formulation.