DE102005034348A1 - Hydroxy-functional lacquer formulations contain hardener-reactive organosilane surface-treated particles which increase the coating scratch resistance at low contents - Google Patents

Abstract

A coating formulation contains particles (P) obtained by reacting a colloidal metal- or silicon-oxide sol with an organosilane, the formulation comprising the following components (a)-(c) by weight based on solids content and (d) as a percentage based on total formulation weight (A) a hydroxy group-functional lacquer resin (L) (20-90%); (B) a hardener (H) which contains optionally protected isocyanate groups or is a melamine-formaldehyde resin or a tri(aminocarbonyl)triazine (1-90%); (C) particles (P) having surface functions reactive with hardener (H) (0.05-5%); and (D) a solvent (mixture) (0-90%). A coating formulation contains particles (P) obtained by reacting a colloidal metal- or silicon-oxide sol with an organosilane of formula (R 1>O) 3-n(R 2>) nSi-A-X (I) or (II), the formulation comprising the following components (a)-(c) by weight based on solids content and (d) as a percentage based on total formulation weight (A) a hydroxy group-functional lacquer resin (L) (20-90%); (B) a hardener (H) which contains optionally protected isocyanate groups or is a melamine-formaldehyde resin or a tri(aminocarbonyl)triazine (1-90%); (C) particles (P) having surface functions reactive with hardener (H) (0.05-5%); and (D) a solvent (mixture) (0-90%). R 1>H, (cyclo)alkyl or aryl of 1-6C with the carbon chain optionally interrupted by non-adjacent O, S or NR 3>; R 2>H, (cyclo)alkyl, aryl or aralkyl of 1-12C with the carbon chain optionally interrupted as for R 1>; R 3>H, (cyclo)alkyl, aryl, aralkyl, aminoalkyl or an aspartate ester group; R 4>H or a suitable organic group; A : a divalent (cyclo)alkyl or aryl group of 1-10C with the carbon chain optionally interrupted as for R 1>; X : an organo-function able to chemically react with (H) during the hardening of the lacquer; Y : an organo-function able to chemically react with (H) (optionally after the splitting of the Si-Y bond) during the hardening of the lacquer; n and m : 0, 1 or 2; and q : 0 or 1. [Image].

Description

The Invention relates to coating formulations containing particles which have been modified with organofunctional silanes, and their use as paints.

Particles - in particular nanoparticles - containing coating systems are state of the art. Corresponding coatings are for example in EP 1 249 470 , WO 03/16370, US 20030194550 or US 20030162015 described. The particles lead to an improvement in the properties of the corresponding coatings, in particular with regard to their scratch resistance and optionally also their chemical resistance.

One often occurring problem when using the - usually inorganic - particles in organic coating systems consists in a mostly insufficient compatibility of particles and paint matrix. This can cause the particles do not disperse sufficiently well in a paint matrix. moreover can self-dispersed particles for longer standstill or storage times settle, with possibly larger aggregates or agglomerates form, which also in a redispersion not or only bad in the original ones Let particles separate. The processing of such inhomogeneous Systems is extremely difficult in any case often impossible. Lacquers which have smooth surfaces after being applied and cured in this way usually not or only after costly Produce process.

It is therefore advantageous to use particles which have organic groups on their surface which lead to better compatibility with the coating matrix. In this way, the inorganic particle is "masked" by an organic shell, in which case particularly favorable coating properties can be achieved if the organic functions on the particle surfaces are also reactive with respect to the coating matrix, so that under the respective curing conditions of the corresponding coating material In this way, it is possible to chemically incorporate the particles into the matrix during coating curing, which often results in particularly good mechanical properties as well as improved chemical resistance DE 102 47 359 A1 . EP 832 947 A or EP 0 872 500 A1 described. Disadvantages of the systems described here are generally relatively high proportions of the comparatively expensive nanoparticles in the total solids content of the paint.

Furthermore, the use of coatings containing a nanoparticle-modified binder is also known. These can be prepared by reacting the reactive functionalized particles with a binder having a complementary function. Ie. Here, the organofunctional particle is chemically incorporated into the paint matrix not only during paint curing but also during binder production. Such systems are for example in EP 1 187 885 A or WO 01/05897. However, they have the disadvantage of being relatively expensive to produce, which leads to high production costs.

at A particularly important type of lacquer is a lacquer resin made of hydroxy-functional Prepolymers, in particular of hydroxy-functional polyacrylates and / or polyesters used in lacquer curing an isocyanate-functional hardener (Polyurethane coatings) and / or a melamine hardener (melamine coatings) for the reaction to be brought. The polyurethane coatings are characterized by especially good qualities. For example, polyurethane coatings have a superior quality Chemical resistance, while the melamine coatings usually over have better scratch resistance.

typically, These types of paint are in particularly high quality and demanding Application areas used, for example as clearcoats or topcoats for OEM coatings in the automotive and vehicle industry. Likewise also exist the most topcoats for Automotive repairs from such systems. The layer thicknesses These paints are typically in the range of 20 to 50 microns.

In polyurethane paint systems, a distinction is generally made between the so-called 2K and 1K systems. The former consist of two components, one of which consists essentially of the Isocyanathärter, while the paint resin is contained with its isocyanate-reactive groups in the second component. Both components must be stored and transported separately and may only be mixed shortly before processing, since the finished mixture has only a very limited pot life. Often cheaper are therefore the so-called 1K systems, which consist of only one component, in the in addition to the paint resin, a hardener with protected isocyanate groups is present. 1-component coatings are thermally cured, whereby the protective groups of the isocyanate units are split off and the deprotected tiocyanates can subsequently react with the coating resin. Typical baking temperatures of such 1K paints are 120-160 ° C. Melamine paints are usually 1-component paints; the baking temperatures are typically within a comparable temperature range.

Especially would be with these high quality paints another property improvement desirable. This is especially true for vehicle topcoats. So, above all, the achievable scratch resistance of conventional Car paints not yet sufficient, so that it z. B. in the car wash through Particles in the wash water to a noticeable scratching of the paint comes. In the long term, the gloss of the paint is sustainably damaged. Here would be formulations desirable, with which better scratch resistance can be achieved.

One particularly advantageous way to solve this problem is the Use of particles having organofunctions on their surface the opposite the paint resin or opposite Reactive to the hardener are. In addition, lead these organ functions on the particle surface to mask the Particles and thus improve the compatibility of particles and Paint matrix.

Such particles with suitable organ functions are already known in principle. They are, as well as their use in coatings, for example in EP 0 768 351 . EP 0 832 947 . EP 0 872 500 or DE 10247359 described.

In fact, it is possible the scratch resistance of paints through the incorporation of such particles noticeably increase. However, all of the prior art described method when using these particles still no achieved optimal results. In particular, have the corresponding Coatings such high particle contents on that a use of such paints in big Series painting is difficult to realize for cost reasons alone will be.

In WO 01/09231 describes particle-containing paint systems which characterized in that in a surface segment of the paint more particles than in a bulk segment. Advantage of this Particle distribution is the comparatively low particle concentration, the for a significant improvement in scratch resistance is needed. The desired high affinity the particle to the paint surface is achieved by focusing on the particle surfaces Silicone resin as a surface-active Apply agent. The so available Modified particles have a relative - often typical for silicones low surface energy. As a result, they prefer to arrange themselves on the surface of the Paint matrix on. A disadvantage of this method, however, is the Fact that not only the silicone resin modification of the particles, but also the production of the required silicone resins themselves is technically complicated. The latter is therefore particularly problematic because it is for the achievement of a good scratch resistance is necessary, the silicone resins with organ functions, e.g. As carbinol functions to provide over the the correspondingly modified particles during paint curing chemically can be installed in the paint. Such functionalized silicone resins are not commercially or only very limited available. Above all, the selection of the possible organ functions is also included relatively limited in this system. Therefore, in this system, as with all other systems according to the prior art, not yet achieved optimal results.

task The invention was therefore the development of a paint system that the Overcomes disadvantages according to the prior art.

• a) 20–90 Gew.-%, bezogen auf den Feststoffanteil, eines hydroxylgruppen-funktionellen Lackharzes (L),
• b) 1–90 Gew.-%, bezogen auf den Feststoffanteil, eines Lackhärters (H), der ausgewählt wird aus geschützte oder ungeschützte Isocyanatgruppen enthaltenden Lackhärtern, Melamin-Formaldehyd-Harzen und Tris(aminocarbony)triazinen,
• c) 0,05–5 Gew.-%, bezogen auf den Feststoffanteil, an Partikeln (P), die auf ihrer Oberfläche über, gegenüber dem Lackhärter (H), reaktive Funktionen verfügen,
• d) 0–90 Gew.-%, bezogen auf die gesamte Beschichtungsformulierung (B), eines Lösungsmittels oder eines Lösungsmittelgemisches enthalten, bei dem die Partikel (P) erhältlich sind durch eine Umsetzung kolloidaler Metall- oder Siliciumoxidsole (P1) mit Organosilanen (A), die aus den allgemeinen Formeln (I) und (II)
  

ausgewählt werden, wobei
R¹ Wasserstoff, Alkyl-, Cycloalkyl- oder Arylreste mit jeweils 1 bis 6 C-Atomen, wobei die Kohlenstoffkette durch nicht benachbarte Sauerstoff-, Schwefel- oder NR³-Gruppen unterbrochen sein kann,
R² Alkyl-, Cycloalkyl-, Aryl- oder Arylalkylreste mit jeweils 1 bis 12 C-Atomen, wobei die Kohlenstoffkette durch nicht benachbarte Sauerstoff-, Schwefel- oder NR³-Gruppen unterbrochen sein kann,
R³ Wasserstoff, Alkyl-, Cycloalkyl-, Aryl-, Arylalkyl-, Aminoalkyl- oder Aspartatesterreste,
R⁴ Wasserstoff oder einen beliebigen organischen Rest,
A einen zweibindigen, gegebenenfalls substituierten Alkyl-, Cycloalkyl- oder Aryl-Rest mit 1–10 Kohlenstoffatomen, der gegebenenfalls durch Sauerstoff-, Schwefel- oder NR³-Gruppen unterbrochen sein kann,
X eine Organofunktion, die bei der Lackhärtung eine chemische Reaktion mit dem Härter (H) eingehen kann,
Y eine Organofunktion, die – gegebenenfalls nach der Spaltung der Si-Y-Bindung – bei der Lackhärtung eine chemische Reaktion mit dem Härter (H) eingehen kann, bedeuten und
n die Werte 0, 1 oder 2,
m die Werte 0, 1 oder 2 und
q die Werte 0 oder 1 annehmen können.The invention relates to coating formulations (B) which

• a) 20-90 wt .-%, based on the solids content, of a hydroxyl-functional paint resin (L),
• b) 1-90% by weight, based on the solids content, of a coating hardener (H) which is selected from coating hardeners containing protected or unprotected isocyanate groups, melamine-formaldehyde resins and tris (aminocarbony) triazines,
• c) 0.05-5% by weight, based on the solids content, of particles (P) which have reactive functions on their surface over the paint hardener (H),
• d) 0-90 wt .-%, based on the total coating formulation (B), of a solvent or a solvent mixture, wherein the particles (P) are obtainable by a reaction of colloidal metal or Siliciumoxidsole (P1) with organosilanes (A ), consisting of the general formulas (I) and (II)
  

be selected, where
R ^{1 is} hydrogen, alkyl, cycloalkyl or aryl radicals having in each case 1 to 6 C atoms, where the carbon chain may be interrupted by nonadjacent oxygen, sulfur or NR ³ groups,
R ^{2 is} alkyl, cycloalkyl, aryl or arylalkyl radicals having in each case 1 to 12 C atoms, where the carbon chain may be interrupted by nonadjacent oxygen, sulfur or NR ³ groups,
R ^{3 is} hydrogen, alkyl, cycloalkyl, aryl, arylalkyl, aminoalkyl or aspartate ester radicals,
R ^{4 is} hydrogen or any organic radical,
A is a divalent, optionally substituted alkyl, cycloalkyl or aryl radical having 1-10 carbon atoms, which may optionally be interrupted by oxygen, sulfur or NR ³ groups,
X is an organo function that can undergo a chemical reaction with the hardener (H) during paint hardening,
Y is an organo function which, if appropriate after the cleavage of the Si-Y bond, can undergo a chemical reaction with the hardener (H) during paint curing, and
n the values 0, 1 or 2,
m is the values 0, 1 or 2 and
q can take the values 0 or 1.

Of the Solids content includes those paint components, the at the lacquer hardening remain in the paint.

Of the Invention is based on the discovery that in use the particles (P) in coating formulations, in particular coating systems the scratch resistance of the resulting paints is not proportional changes to the concentration of the particles used. So on the contrary already described the small or very small contents of particles (P) to significantly improve the scratch resistance of clearcoats to achieve, whereas you can also by z. T. significantly higher proportions on particles (P) no further significant increase in scratch resistance can achieve more.

The allow small contents of the usually relatively expensive particles (P) on the one hand, a comparatively cost-effective production of highly scratch-resistant Paints, on the other hand, the low particle contents reduce the - if necessary negative influences of Particles on other paint properties, such. B. the elasticity or transparency and surface smoothness of the Paint. At the same time, the production of the particles according to the invention from particle sols (P1) and the silanes (A), which are mostly already through Simple mixing of both components can be carried out, very easy. Thus, the coating formulations according to the invention provide (B) with low levels of synthetically accessible Particles a big one advantage over the prior art.

• a) 30–80 Gew.-%, bezogen auf den Feststoffanteil, eines hydroxylgruppen-funktionellen Lackharzes (L),
• b) 10–60 Gew.-%, bezogen auf den Feststoffanteil, eines Lackhärters (H),
• c) 0,1–4 Gew.-%, bezogen auf den Feststoffanteil, an Partikeln (P) und
• d) 10–70 Gew.-%, bezogen auf die gesamte Beschichtungsformulierung (B), eines oder mehrerer Lösungsmittel.

In a preferred embodiment of the invention, the coating formulations (B) contain

• a) 30-80 wt .-%, based on the solids content of a hydroxyl-functional paint resin (L),
• b) 10-60% by weight, based on the solids content, of a paint curing agent (H),
• c) 0.1-4 wt .-%, based on the solids content of particles (P) and
• d) 10-70% by weight, based on the total coating formulation (B), of one or more solvents.

• a) 40–70 Gew.-%, bezogen auf den Feststoffanteil, eines hydroxylgruppen-funktionelles Lackharzes (L),
• b) 15–50 Gew.-%, bezogen auf den Feststoffanteil, eines Lackhärters (H),
• c) 0,5–3 Gew.-%, bezogen auf den Feststoffanteil, an Partikeln (P) und
• d) 10–70 Gew.-%, bezogen auf die gesamte Beschichtungsformulierung (B), eines oder mehrerer Lösungsmittel.

The coating formulations (B) particularly preferably contain

• a) 40-70 wt .-%, based on the solids content of a hydroxyl-functional paint resin (L),
• b) 15-50% by weight, based on the solids content, of a paint curing agent (H),
• c) 0.5-3 wt .-%, based on the solids content of particles (P) and
• d) 10-70% by weight, based on the total coating formulation (B), of one or more solvents.

Especially Preferably, the proportion of the solvent or of the total Coating formulation (B) at 10 to 50 wt .-%.

The Paint resin (L), the particles (P) and the paint hardener (H) preferably have a sufficient number of reactive groups that harden during curing Coating formulation (B) a three-dimensional polymer network can train.

The Coating formulations according to the invention (B) are preferred as paints, more preferably as clear and / or Topcoats used, especially for automotive OEM or automotive refinish.

In the case of the organosilanes (A), the groups R ^{1 are} preferably methyl or ethyl radicals. The groups R ² preferably represent alkyl radicals having 1-6 carbon atoms or phenyl radicals, in particular methyl, ethyl or isopropyl radicals. R ³ preferably has at most 10 carbon atoms, in particular at most 4 carbon atoms. R ⁴ preferably represents hydrogen or an alkyl radical having 1-10, particularly preferably 1-6, carbon atoms, in particular methyl or ethyl radicals. A is preferably a divalent alkyl radical having 1-6 carbon atoms, which may optionally be interrupted by oxygen, sulfur or NR ³ groups. A particularly preferably represents a (CH ₂ ) ₃ group or a CH ₂ group.

X preferably represents a hydroxyl or thiol function, a group of the formula NHR ⁵ , a heterocyclic ring containing an NH function or an epoxide ring. In a preferred embodiment, X represents a piperazine ring.

R ⁵ has the meanings of R ³ . If X represents an epoxide ring, this is before, during or after the reaction of the silane (A) with the particles (P1) by a suitable method, for. B. by a reaction with ammonia, an amine, water or an alcohol or an alcoholate, opened.

If silanes (A) of the general formula (II) are used in the preparation of the particles (P), the ring structure of this silane is broken during particle production by the attack of a hydroxyl group of the particles (P1) on the silicon atom of the silane (A) the Si-Y bond opened. In this case, X is preferably a function which, after this cleavage of the Si-Y bond, represents a hydroxyl or thiol function or a group of the formula NHR ⁵ .

wobei
R ein Sauerstoffatom, ein Schwefelatom, eine Carbonylgruppe, eine Estergruppe, eine Amidgruppe oder eine NR⁶-Gruppe darstellt,
R⁶ die Bedeutungen von R³ aufweist,
x die Werte von 0 bis 10 annehmen kann
und die übrigen Variablen die bei den allgemeinen Formeln (I) und (II) angegebenen Bedeutungen aufweisen.Particular preference is given to using organosilanes (A) which correspond to the general formulas (III) or (IIIa)

in which
R represents an oxygen, sulfur, carbonyl, ester, amide or NR ⁶ group,
R ^{6 has} the meanings of R ³ ,
x can take values from 0 to 10
and the other variables have the meanings given in the general formulas (I) and (II).

wobei sämtliche Variablen die bei den allgemeinen Formeln (I)–(III) angegebenen Bedeutungen aufweisen.In a further particularly preferred embodiment of the invention, the particulate sols (P1) are functionalized with organosilanes (A) which correspond to the general formulas (IV) or (IVa)

all variables having the meanings given in the general formulas (I) - (III).

wobei sämtliche Variablen die oben angegebenen Bedeutungen aufweisen.Very particular preference is given to using organosilanes (A) as compounds of the general formulas (V) or (VI)

where all variables have the meanings given above.

at The preparation of the particles (P) can be used for surface modification the particle brine (P1) in addition to the silanes (A) and any mixtures the silanes (A) with other silanes (S1), silazanes (S2) or siloxanes (S3) are used. The silanes (S1) have either hydroxysilyl groups or over hydrolyzable silyl functions, the latter being preferred. In addition, you can these silanes about more Have organ functions, it can but also silanes (S1) can be used without further organ functions. As silazanes (S2) or siloxanes (S3) are particularly preferred Hexamethyldisilazane or hexamethyldisiloxane used. Prefers is the proportion by weight the silanes (A) in the total amount consisting of the silanes (A) and (S1), Silazanes (S2) and siloxanes (S3) is formed, at least 50 wt .-%, particularly preferably at least 70 wt .-% or 90 Wt .-%. In a further particularly preferred embodiment of the Invention is directed to the use of compounds (S1), (S2) and (S3) Completely waived.

at the production of the particles (P) is dependent on colloidal silicon or metal oxide sols (P1), which are generally referred to as Dispersion of the corresponding sub-micron size oxide particles in an aqueous or non-aqueous solvent available. It can including the oxides of the metals aluminum, titanium, zirconium, Tantalum, tungsten, hafnium and tin are used. Preferably used becomes colloidal silica. These are generally to a dispersion of silica particles in an aqueous or non-aqueous Solvent. As a rule, the silica sols are 1-50% by weight Solutions, preferably around 20-40 % By weight solutions. Such sols are commercially available and are available from numerous Manufacturers (e.g., DuPont, Nalco Chemical Company, Nissan Chemicals Etc). Typical solvents are in addition to water, especially alcohols, especially alcohols with 1 to 6 carbon atoms, preferably monohydric alcohols, often isopropanol but also other, usually low molecular weight alcohols, such as. Methanol, Ethanol, n-propanol, n-butanol, isobutanol and t-butanol. As well are also organosols in polar aprotic solvents, such. Methyl ethyl ketone, or aromatic solvents, such as As toluene, available. The mean particle size of the silica particles (P1) is generally 1-100 nm, preferably at 5-50 nm, more preferably 8-30 nm.

The preparation of the particles (P) from the colloidal silicon or metal oxides (P1) and the organosilanes (A) preferably takes place directly during the mixing of the reactants - if appropriate in the presence of further solvents and / or water. The order of addition of the individual reactants is arbitrary. However, preference is given to adding the silanes (A) - optionally in a solvent and / or in mixtures with other silanes (S1), silazanes (S2) or siloxanes (S3) - to the aqueous or organic particulate sol (P1). This sol is optionally acidic, z. By hydrochloric acid or trifluoroacetic acid, or basic, e.g. B. by ammonia stabilized. The reaction is usually carried out at temperatures of 0-200 ° C, preferably at 20-80 ° C and more preferably at 20-60 ° C. The reaction times are typically from 5 minutes to 48 hours, preferably from 1 to 24 hours. Alternatively, it is also possible to add acidic, basic or heavy metal-containing catalysts. However, preference is given to omitting the addition of separate catalysts.

There the colloidal silicon or metal oxide sols (P1) often in aqueous or alcoholic dispersion, it may be advantageous the solvent (s) while or after the preparation of the particles (P) against another solvent or against another solvent mixture exchange. This can be done, for example, by distillative removal of the original one solvent done, taking the new solvent or solvent mixture in one or in several steps before, during or even after the Distillation can be added. Suitable solvents can thereby For example, water, aromatic or aliphatic alcohols, wherein monohydric aliphatic alcohols, especially aliphatic alcohols with 1 to 6 carbon atoms (eg, methanol, ethanol, n-propanol, Isopropanol, n-butanol, isobutanol, t-butanol, the various Regioisomers of pentanol and hexanol), esters (e.g. Ethyl acetate, propyl acetate, butyl acetate, butyl diglycol acetate, Methoxypropyl acetate), ketones (e.g., acetone, methyl ethyl ketone), ethers (eg, diethyl ether, t-butyl methyl ether, THF), aromatic solvents (Toluene, the various regioisomers of xylene but also mixtures such as solvent naphtha), lactones (eg butyrolactone etc.) or lactams (eg, N-methylpyrrolidone). This aprotic solvents or solvent mixtures, the exclusively or at least partially consist of aprotic solvents, preferably. Aprotic solvents are at least when used in isocyanate-curing Coating Formulations (B), d. H. in 1K or 2K polyurethane coatings, advantageous since protic solvents as well like water reactive towards Isocyanate functions are what causes undesirable side reactions between Harder (H) and the solvent to lead can. In addition to the production of a particle dispersion is also a Isolation of the particles (P) conceivable as a solid, z. B. by distillative removal of the solvent (s) after particle preparation.

In a particularly advantageous embodiment of the invention, in the preparation of the particles (P) silanes (A) of the general formula (I) or (VI) in which the spacer A is a CH ₂ bridge, or cyclic silanes of the formulas (III), (IIIa), (IVa) or (V) used. These silanes are characterized by a particularly high reactivity towards the hydroxyl groups of the particles (P1), so that the functionalization of the particles can be carried out particularly rapidly and at low temperatures, in particular already at room temperature.

Become while silanes (A) are used, which only monofunctional silyl functions feature, d. H. Silanes of the general formulas (I), (II), (III), (IIIa), (IV), (IVa), (V) or (VI) with n or m = 2, so in the preparation the particle (P) to be dispensed with the addition of water, since the monoalkoxysilyl groups or the reactive cyclic silanes react directly with the hydroxyl functions on the surface of the particles (P1) can. However, silanes (A) with di- or trifunctional silyl groups used (i.e., silanes of the general formulas ((I), (II), (III), (IIIa), (IV), (IVa) or (VI) with n or m = 0 or 1), then the Presence or addition of water in the production of the particles (P) often advantageous because the alkoxysilanes then not only with the Si-OH functions the particle (P1), but - after their hydrolysis - too can react with each other. This results in particles (P), which crosslinked via a shell of each other Silanes (A).

The in the coating formulations according to the invention (B) contained coating resins (L) preferably consist of hydroxyl-containing Prepolymers, more preferably from hydroxyl-containing polyacrylates or polyesters. Such for the paint preparation are suitable hydroxyl-containing polyacrylates and polyesters the skilled person known and relevant Literature often described. They are from numerous manufacturers manufactured and sold commercially.

at The coating formulations (B) may be 1-component (1) or 2-component (2K) paints. In the first case will be as a paint hardener (H) preferably melamine hardener, Tris (aminocarbony) triazines and / or hardeners which have protected isocyanate groups used. In the second case be used as a hardener (H) preferably compounds with free isocyanate groups used. Both melamine hardener as also hardener with protected or unprotected NCO groups are well known as prior art and often described in the relevant literature. You too are commercially available and are distributed by numerous manufacturers.

In a preferred embodiment of the invention, the paint hardener (H) contains free or protected Isocyanate groups. Most commonly used for this purpose di- and / or polyisocyanates, which may have been previously provided with the respective protective groups. As isocyanates, it is possible in principle to use all customary isocyanates, as are frequently described in the literature. Common diisocyanates are, for example, diisocyanatodiphenylmethane (MDI), both in the form of crude or industrial MDI and in the form of pure 4,4'- or 2,4'-isomers or mixtures thereof, tolylene diisocyanate (TDI) in the form of its various regioisomers, diisocyanato naphthalene (NDI), isophorone diisocyanate (IPDI), perhydrogenated MDI (H-MDI), tetramethylene diisocyanate, 2-methylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1,3-diisocyanato-4-methylcyclohexane or hexamethylene diisocyanate (HDI). Examples of polyisocyanates are polymeric MDI (P-MDI), triphenylmethane triisocyanate and also all isocyanurate or biuret trimers of the diisocyanates listed above. In addition, it is also possible to use further oligomers of the abovementioned isocyanates with blocked NCO groups. All di- and / or polyisocyanates can be used individually or in mixtures. Preference is given here to the isocyanurate and biuret trimerates of the comparatively UV-stable aliphatic isocyanates, particularly preferably the trimers of HDI and IPDI.

Become as a hardener (H) isocyanates with protected Isocyanate groups are used, then protective groups are preferred, at temperatures of 80 to 200 ° C, more preferably at 100 up to 170 ° C be split off. As protecting groups, secondary or tertiary alcohols, such as isopropanol or t-butanol, CH-acid Compounds, such. For example, diethyl malonate, Acetylacetone, ethyl acetoacetate, Oximes, such as. Formaldoxime, acetaldoxime, butanoxime, cyclohexanone oxime, Acetophenone oxime, benzophenone oxime or diethylene glycol, lactams, such as Caprolactam, valerolactam, butyrolactam, phenols, such as Phenol, o-methylphenol, N-alkylamides, such as N-methylacetamide, imides such as phthalimide, secondary amines, such as Diisopropylamine, imidazole, 2-isopropylimidazole, pyrazole, 3,5-dimethylpryazole, 1,2,4-triazole and 2.5 dimethyl-1,2,4-triazole, are used. Preferably, protecting groups such as butane oxime, 3,5-dimethylpyrazole, Caprolactam, diethyl malonate, Malonsäuredemethylester, Acetoacetic ester, diisopropylamine, pyrrolidone, 1,2,4-triazole, imidazole and 2-isopropylimidazole. Particularly preferred are protecting groups used, which allow a low baking temperature, such as For example, diethyl malonate, dimethyl malonate, Butanoxime, diisopropylamine, 3,5-dimethylpyrazole and 2-isopropylimidazole.

The relationship if necessary blocked - isocyanate groups all Components of the coating formulation (B) to the isocyanate-reactive Groups of all Components of the coating formulation (B) usually become from 0.5 to 2, preferably from 0.8 to 1.5, and more preferably chosen from 1.0 to 1.2.

Of course they are the organo-functions of the particle-modification Silanes (i.e., the X or Y functions in the general formulas (I) and (II), the functions of the paint resin (L) and the hardener (H)) suitably coordinated with each other.

Of Further can the coating formulations (B) also the common solvents and the usual in paint formulations Additives and paint components as component (E) included. To call would be here u. a. Flow control agents, surface-active substances, adhesion promoters, Sunscreens such as UV absorbers and / or radical scavengers, thixotropic agents as well as other solids. To generate the respectively desired Property profiles of both the coating formulations (B) as also the cured paints become such additives preferably added. Likewise the coating formulations (B) also contain pigments.

at A preferred method are the coating formulations according to the invention (B) prepared by the particles (P) during the mixing process as Powder or as a dispersion in a suitable solvent. In addition, however, another method is preferred in which the particles (P) and one or more paint components first Masterbatch is produced, with particle concentrations> 15 wt .-%, preferably> 25 wt .-% and especially preferably> 30% by weight. In the preparation of the coating formulations according to the invention (B) this masterbatch is then mixed with the other paint components. Used in the production of the masterbatch from a particle dispersion it may be advantageous if the solvent particle dispersion during masterbatch production is, for. B. over a distillation step, or against another solvent or solvent mixture is exchanged.

With the coatings (B) according to the invention, it is possible to coat any desired substrates for improving scratch resistance, abrasion resistance or chemical resistance. Preferred substrates are plastics such as polycarbonate, polybutylene terephthalate, polymethyl methacrylate, polystyrene or polyvinyl chloride as well as applied in an upstream step basecoats.

Especially The coatings of the invention preferably serve as scratch-resistant Clear or topcoats, especially in the automotive industry. The Application of the coating formulations (B) may be by any Methods such as dipping, spraying, and casting process respectively. Also application of the coating formulation (B) on a basecoat after a "wet in wet "process is possible. The curing usually done by heating under the conditions required (2K paints typically at 0-100 ° C, preferred at 20-80 ° C, 1-component paints at 100-200 ° C preferred at 120-160 ° C). Of course you can the lacquer hardening be accelerated by the addition of suitable catalysts. Particularly suitable catalysts are acidic, basic ones as well as heavy metal containing compounds.

All Symbols of the above formulas have their meanings, respectively independently from each other. In all formulas, the silicon atom is tetravalent.

So far Unless otherwise indicated, all amounts and percentages are on the weight, all pressures 0.10 MPa (abs.) And all temperatures 20 ° C.

Synthesis Example 1: Preparation of 1,1-dimethyl-1-sila-2,5-dioxacyclohexane (Silane 1).

One Mixture of 103.9 g (0.75 mol) of chloromethyldimethylmethoxysilane, 46.6 g (0.75 mol) of ethylene glycol and 200 ml of 1,4-diisopropylbenzene be at 150 ° C heated and stirred for 3 h. In this case, 24 g of methanol are distilled off. Then slowly at 150 ° C Added dropwise 138.8 g (0.75 mol) of tributylamine. After the dropping is for further 3 h at 150 ° C touched. The resulting salt is filtered off. The filtrate is fractionated distilled, wherein the fraction passing at 132 ° C 26.0 g pure 1,1-dimethyl-1-sila-2,5-dioxacyclohexane receives.

Synthetic Example 2: Preparation of N-butyl-1,1-trimethyl-1-sila-2-azacyclopentane (Silane 2).

To a template of 508 g (6.94 mol) of 1-butylamine are inside Added dropwise from 2.5 h 171 g (1.00 mol) of chloropropyldimethylchlorosilane and the mixture is for 12 h under reflux heated. After distilling off the excess 1-butylamine is the Residue diluted with 350 ml of toluene and at 10 ° C cooled. The precipitate formed is filtered off and the filtrate distilled in vacuo. You get 134.5 g of N-butyl-1,1-dimethyl-1-sila-2-azacyclopentane.

Synthesis Example 3: Preparation of N-triethoxysilylmethylpiperazine (Silane 3).

905.3 g (10.5 mol) of piperazine and 945 ml of xylene (anhydrous) as solvent are presented in a 4 liter 4-necked flask and then with Nitrogen inertized. It is heated to a temperature of 100 ° C, wherein the piperazine completely solves. at 446.3 g (2.1 mol) of chloromethyltriethoxysilane are added dropwise at this temperature within 1 hour with good stirring to. It falls after the addition of about 1/3 of the amount of silane piperazine hydrochloride as a salt, but the suspension remains until the end of the reaction good to stir. Stirring is complete after completion of the addition one for one another 15 minutes after. Subsequently the reaction mixture is at 110 ° C heated and the precipitated salt over a preheated filter filtered off.

you cools down about 5 ° C and filtered from the precipitated at this temperature piperazine excess. Subsequently distilled the solvent from, with any remaining piperazine residues also removed become. The crude product thus obtained is purified by distillation (84-86 ° C at 0.1 mbar). There is a yield of 357.5 g (1.36 mol), d. H. about 65% based on the amount of silane used.

Synthesis Example 4: Preparation of carbinol-functional SiO ₂ nanosol particles

At a temperature of 25 ° C to 50.0 g of a SiO ₂ organosol (IPA-ST ^® from Nissan Chemical, 30.5 wt .-% SiO ₂ in isopropanol, average particle size 12 nm), 1.98 g (14.9 mmol) of silane 1 was added. The mixture is stirred for 6 h at 50 ° C and for a further 24 h at room temperature to give a substantially clear suspension showing a weak Tyndall effect. It has a solids content of 33.15 wt .-%, an SiO ₂ content of 29.34 wt .-%, and an OH group content of 0.28 mmol / g.

Synthesis Example 5: Preparation of aminoalkyl-functional SiO ₂ nanosol particles

To 11.0 g of a diluted silica sol, which by adding 7.5 g of isopropanol to 3.5 g of the silica sol IPA-ST ^® from Nissan Chemical (30.5 wt .-% SiO ₂ in isopropanol, average particle size 12 nm ), a solution of 0.085 g of the silane 2 described in Synthesis Example 2 in 0.4 g of ethanol is added dropwise rapidly and the reaction mixture is stirred for 1 h at room temperature. The modified silica sol, which shows a slight Tyndall effect, has a solids content of 10.0% by weight, an SiO ₂ content of 9.3% by weight and an NH group content of 0.04 mmol / g ,

Synthesis Example 6: Preparation of aminoalkyl-functional SiO ₂ nanosol particles

To 11.0 g of a diluted silica sol obtained by adding 7.5 g of isopropanol 3.5 g of the silica sol IPA-ST ^® from Nissan Chemical (30.5 parts by weight SiO ₂ in isopropanol, average particle size 12 nm) has been obtained, a solution of 0.095 g of the silane 3 described in Synthesis Example 3 in 0.4 g of ethanol is rapidly added dropwise and the reaction mixture stirred for 1 h at room temperature. The modified silica sol, which shows a slight Tyndall effect, has a solids content of 9.7% by weight, an SiO ₂ content of 9.3% by weight and an amine content of 0.03 mmol / g.

Examples 1-3: Preparation of 1K coating formulations containing SiO ₂ nanosol particles modified with carbinol functions

Tabelle 1: Rezepturen der Lacke (Beispiel 1–3)

• * nicht erfindungsgemäss
• ¹⁾ Anteil der Partikel nach Synthesebeispiel 4 am gesamten Festgehalt der jeweiligen Lackformulierung Herstellung und Bewertung von Lackfilaten aus den Lackformulierungen der Beispiele 1–3.

To prepare a coating formulation according to the invention, an acrylate-based coating polyol having a solids content of 52.4% by weight (solvent: solvent naphtha, methoxypropyl acetate (10: 1)), a hydroxyl group content of 1.46 mmol / g resin solution and an acid number of 10 15 mg KOH / g 3175 SN from. Bayer mixed with Desmodur ^® BL (butanoxime-blocked polyisocyanate, blocked NCO content of 2.64 mmol / g). The amounts of the respective components used can be found in Table 1. Subsequently, the amounts indicated in Table 1 of the dispersions prepared according to Synthesis Example 4 are added. In each case, molar ratios of protected isocyanate functions to hydroxyl groups of about 1.1: 1 are achieved. Further be admixed in each case 0.01 g of dibutyltin dilaurate and 0.03 g of a 10% solution ADDID ^® 100 from. TEGO AG (flow control agents based on polysiloxanes) in isopropanol to give coating formulations are obtained with about 50% solids content. These initially slightly cloudy mixtures are stirred for 48 h at room temperature to give clear coating formulations.

Table 1: Formulations of the lacquers (Example 1-3)

• * not according to the invention
• ¹⁾ proportion of particles according to Synthesis Example 4 in the total solids content of the respective paint formulation Preparation and evaluation of paint filaments from the paint formulations of Examples 1-3.

The coating compositions of Examples 1-4 are each by means of a film applicator Coatmaster ^® 509 MC Fa.

Erichsen with a squeegee of the gap height 120 μm a glass plate aufgerakelt. Subsequently, the obtained Coating films in a convection oven for 30 minutes at 70 ° C and subsequently for 30 Min. At 150 ° C dried. Both from the paint formulations of the examples as Also from the comparative examples are optically flawless, smooth Coatings obtained.

Tabelle 2: Glanzverlust beim Kratztest nach Peter-Dahn

• * nicht erfindungsgemäss

The gloss of the coatings is determined with a gloss meter Micro gloss 20 ° from Byk and is in all paint formulation between 159 and 164 gloss units. The scratch resistance of the cured coating films produced in this way is determined using a scouring tester according to Peter-Dahn. For this purpose a scouring fleece Scotch ^Brite® 2297 with a surface of 45 × 45 mm weighing 500 g is weighted. With this, the paint samples are scratched with a total of 40 strokes. Both before and after completion of the scratching tests, the gloss of the respective coating is measured with a gloss meter Micro gloss 20 ° from Byk. As a measure of the scratch resistance of the respective coating, the loss in gloss was determined in comparison with the starting value:

Table 2: Loss loss in the scratch test according to Peter-Dahn

• * not according to the invention

The Results show that itself smallest contents (3.3% by weight) of the particles (P) according to the invention to a clear Increase the scratch resistance of the corresponding coating lead. Clear higher particle contents (Example 3 - Particle Content: 7% by weight) however, no further increase in scratch resistance.

Examples 4-7: Preparation of 1K coating formulations containing SiO ₂ nanoparticles modified with carbamine functions

Tabelle 3: Rezepturen der Lacke (Beispiel 5–8)

• * Anteil der Partikel nach Synthesebeispiel 5 bzw. 6 am gesamten Festgehalt der jeweiligen Lackformulierung

To prepare a coating formulation according to the invention, an acrylate-based coating polyol having a solids content of 52.4% by weight (solvent: solvent naphtha, methoxypropyl acetate (10: 1)), a hydroxyl group content of 1.46 mmol / g resin solution and an acid number of 10 15 mg KOH / g 3175 SN from. Bayer mixed with Desmodur ^® BL (butanoxime-blocked polyisocyanate, a blocked NCO content of 2.64 mmol / g). The amounts of the respective components used can be found in Table 3. Subsequently, the amounts indicated in Table 3 are added to the dispersion prepared according to Synthesis Example 5 or 6. In each case, molar ratios of protected isocyanate functions to hydroxyl groups of about 1.1: 1 are achieved. Further be admixed in each case 0.01 g of dibutyltin dilaurate and 0.03 g of a 10% solution ADDID ^® 100 from. TEGO AG (flow control agents based on polysiloxanes) in isopropanol to give coating formulations are obtained with about 50% solids content. These initially slightly cloudy mixtures are stirred for 48 h at room temperature to give clear coating formulations.

Table 3: Formulations of the lacquers (Example 5-8)

• * Proportion of the particles according to Synthesis Example 5 or 6 in the total solids content of the respective paint formulation

Production and evaluation of paint films from the paint formulations of Examples 5-8.

The coating compositions of Examples 5-8 are knife in each case by means of a film-drawing device Coatmaster ^® 509 MC Fa. Erichsen with a doctor blade gap height of 120 micrometers on a glass plate. Subsequently, the coating films obtained are dried in a circulating air dryer for 30 minutes at 70 ° C and then for 30 min. At 150 ° C. Both the coating formulations of the examples and of the comparative examples give optically flawless, smooth coatings.

The gloss of the coatings is determined with a gloss meter Micro gloss 20 ° from Byk and is in all paint formulation between 159 and 164 gloss units. The scratch resistance of the cured coating films produced in this way is determined using a scouring tester according to Peter-Dahn. For this purpose a scouring fleece Scotch ^Brite® 2297 with a surface of 45 × 45 mm weighing 500 g is weighted. With this, the paint samples are scratched with a total of 40 strokes. Both before and after completion of the scratching tests, the gloss of the respective coating is measured with a gloss meter Micro gloss 20 ° from Byk.

Tabelle 4: Glanzverlust beim Kratztest nach Peter-Dahn

• * nicht erfindungsgemäss

As a measure of the scratch resistance of the respective coating, the loss of gloss compared to the starting value was determined

Table 4: Loss loss in the scratch test according to Peter-Dahn

• * not according to the invention

Examples 8-10: Preparation of 2K Coating Formulations Containing SiO ₂ Nanosol Particles Modified with Carbamine Functions

to Preparation of a coating formulation becomes an acrylate-based Paint polyol with a solids content of 52.4% by weight (solvent: Solvent naphtha, methoxypropyl acetate (10: 1)), a hydroxyl group content of 1.46 mmol / g resin solution and an acid number from 10-15 mg KOH / g mixed with the nanosol prepared according to Synthesis Example 6. The amounts of the respective components used are shown in Table 4 indicated. The obtained, initially still slightly cloudy Dispersion is for stirred for about 2 h at room temperature, whereby clear and storage-stable mixture is obtained.

Tabelle 2: Rezepturen der Lacke (Beispiel 1–4)

• * Anteil der Partikel nach Synthesebeispiel 5 bzw. 6 am gesamten Festgehalt der jeweiligen Lackformulierung
• ¹⁾ nicht efindungsgemäß

Directly prior to use this film-forming resin component with Desmodur ^® BL 3390 BA / SN of Messrs. Bayer (polyisocyanate, NCO content of 4.63 mmol / g) is mixed as a curing component. The amounts of the respective components used can be found in Table 4. In each case, molar ratios of isocyanate functions to hydroxyl or amine groups of about 1.1: 1 are achieved. Furthermore, in each case 0.01 g of dibutyltin dilaurate and 0.03 g of a 10% solution ADDID ^® 100 from. TEGO AG admixed (leveling agents based on polysiloxane) in isopropanol to give coating formulations are obtained with about 50% solids content.

Table 2: Formulations of the lacquers (Example 1-4)

• * Proportion of the particles according to Synthesis Example 5 or 6 in the total solids content of the respective paint formulation
• ¹⁾ not according to the invention

Production and evaluation of paint films from the paint formulations of Examples 8-10

Immediately after the particular blending of paint resin component and paint component, the coating compositions of Comparative Example 3 and Examples 7-8 are doctored by means of a film applicator Coatmaster ^® 509 MC Fa. Erichsen with a blade of gap height 120 microns on a glass plate. Subsequently, the resulting coating films are dried in a circulating air dryer for 30 minutes at 80 ° C. Both the paint formulations of Examples 7-8 and those of Comparative Example 3 give optically flawless, smooth coatings.

The gloss of the coatings is determined with a gloss meter Micro gloss 20 ° from Byk and is in all paint formulation between 159 and 164 gloss units. The scratch resistance of the cured coating films produced in this way is determined using a scouring tester according to Peter-Dahn. For this purpose a scouring fleece Scotch ^Brite® 2297 with a surface of 45 × 45 mm weighing 500 g is weighted. With this, the paint samples are scratched with a total of 50 strokes. Both before and after completion of the scratching tests, the gloss of the respective coating is measured with a gloss meter Micro gloss 20 ° from Byk.

Tabelle 5: Glanzverlust beim Kratztest nach Peter-Dahn

• ¹⁾ nicht efindungsgemäß

As a measure of the scratch resistance of the respective coating, the loss of gloss is determined in comparison with the starting value:

Table 5: Loss loss in the scratch test according to Peter-Dahn

• ¹⁾ not according to the invention

The Results show that even the smallest contents of the particles according to the invention (P) to a significant increase in the scratch resistance of the corresponding Lead coating.

Claims (10)

Coating formulations (B) which contain a) 20-90% by weight, based on the solids content, of a hydroxyl-functional paint resin (L), b) 1-90% by weight, based on the solids content, of a paint curing agent (H) , which is selected from coated or unprotected isocyanate group-containing lacquer hardeners, melamine-formaldehyde resins and tris (aminocarbony) triazines, c) 0.05-5 wt .-%, based on the solids content, of particles (P), based on their Surface having reactive functions to the paint curing agent (H), d) 0-90 wt .-%, based on the total coating formulation (B), of a solvent or a solvent mixture, wherein the particles (P) are obtainable by a reaction colloidal metal or silicon oxide sols (P1) with organosilanes (A) which are selected from the general formula (I) and (II)

wherein R ^{1 is} hydrogen, alkyl, cycloalkyl or aryl radicals each having 1 to 6 C atoms, wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NR ³ groups, R ^{2 is} alkyl, cycloalkyl , Aryl or arylalkyl radicals having in each case 1 to 12 C atoms, where the carbon chain may be interrupted by nonadjacent oxygen, sulfur or NR ³ groups, R ^{3 is} hydrogen, alkyl, cycloalkyl, aryl, arylalkyl R ^{4 is} hydrogen or any organic radical, A is a divalent, optionally substituted alkyl, cycloalkyl or aryl radical having 1-10 carbon atoms, optionally interrupted by oxygen, sulfur or NR ³ groups X can be an organo function which can undergo a chemical reaction with the curing agent (H) during paint curing, Y an organofunction which, optionally after the cleavage of the Si-Y bond, during paint curing chemical reaction with the hardener (H) can mean, and n the values 0, 1 or 2, m the values 0, 1 or 2 and q can take the values 0 or 1. Coating formulations (B) according to Claim 1, which comprise a) 30-80% by weight, based on the solids content, of a hydroxyl-functional paint resin (L), b) 10-60 wt .-%, based on the solids content of a paint curing agent (H), c) 0.1-4 wt .-%, based on the solids content of particles (P) and d) 10-70 wt %, based on the total coating formulation (B), of one or more solvents. Coating formulations (B) according to Claims 1 and 2, in which groups R ¹ in the organosilanes (A) are methyl or ethyl radicals. Coating formulations (B) according to Claims 1 to 3, in which groups X in the organosilanes (A) of the general formula (I) have a hydroxyl or thiol function, a group of the formula NHR ⁵ , a heterocyclic ring containing an NH function or an epoxide ring in which R ^{5 has} the meanings of R ³ according to claim 1. Coating formulations (B) according to Claims 1 to 3, in which the groups Y in the organosilanes (A) of the general formula (II) are a function which, after cleavage of the Si-Y bond, has a hydroxyl or thiol function or a group of the formula NHR ⁵ according to claim 5. Coating formulations (B) according to Claims 1 to 5, in which organosilanes (A) corresponding to the general formulas (III) or (IIIa) are used

wherein B represents an oxygen atom, a sulfur atom, a carbonyl group, an ester group, an amide group or an NR ⁶ group, R ^{6 has} the meanings of R ³ , x can take the values from 0 to 10 and the remaining variables those in the general Having formulas (I) and (II) according to claim 1 meanings. Coating formulations (B) according to claim 1 to 6, in which the coating resins (L) of hydroxyl-containing polyacrylates or polyesters. Coating formulations (B) according to claim 1 to 7, where as a paint hardener (H) isocyanates with protected Isocyanate groups are used which have protective groups, which are split off at temperatures of 80 to 200 ° C. Coating formulations (B) according to claim 1 to 7, where as a paint hardener (H) isocyanates are used with free isocyanate groups. Use of the coating formulation (B) according to claim 1 to 9 as paints.