DE3917535A1 - Scratch-resistant materials - prepd. by hydrolysis of silane-based mixt. with removal of volatile hydrolysis prods. before applying coating or moulding - Google Patents

Abstract

Scratch-resistant materials (I) are prepd. from a compsn. (II) obtd. by hydrolytic precondensation, opt. in the presence of a catalyst, of (a) 25-95 mol% organofunctional silane(s) of formula (R')mSiX4-m and/or an oligomer thereof, (b) 5-75 mol% cpd(s) of formula AlR3 or MR4 and/or an oligomer therefrom and/or an opt. complexed Al salt of an (in)organic acid and opt. (c) 0-70 mol% soluble in the reaction medium), poorly volatile oxide(s) of element(s) of Main Gp. Ia-Va or Sub Gps. IIb, IIIb, Vb-VIIIb or cpd(s). which form such oxide(s) under the reaction conditions, with less than the amt. of water required for complete hydrolysis of all the hydrolysable gps.; (II) is either (i) further condensed by addn. of more water to effect partial or complete hydrolysis of the remaining gps., then applied to a substrate or subjected to a moulding process, or (ii) applied to a substrate or moulded and then further condensed in an atmos. contg. water vapour, and then hardened; the novelty is that the volatile hydrolysis prods. are partly removed by evapn. at the latest before application to the substrate or moulding. In the formulae: R' = alkyl, alkenyl, alkynyl, aryl, aralkyl, alkylaryl, aralkenyl, alkenylaryl, aralkynyl or opt. substd. alkynylaryl, etc.; X = H, Hal, alkoxy, acyloxy, alkylcarbonyl, alkoxycabronyl or N(R")2 (with R" = H and/or alkyl); m = 1, 2 or 3; R = Hal, alkyl, alkoxy, acyloxy or OH (opt. partly or completely replaced by chelating ligands; M = Ti or Zr. USE/ADVANTAGE - Coatings have considerably higher scratch resistance and wear resistance; the rheological properties and viscosity of the compsn. can be controlled by varying the amt. of volatile prods. removed by evapn., and

Description

Scratch-resistant materials, especially scratch-resistant Coatings, based on inorganic-organic Are polymeric or organically modified silicic acid esters known for a few years and in some cases are also already manufactured on an industrial scale.

EP-A-1 71 493 describes a process for the production scratch-resistant coatings described in which a paint, which has been obtained by hydrolytic precondensation a titanium or zirconium compound and one organofunctional silane and optionally one hardly volatile oxide of an element of main groups Ia to Va or subgroups IVb or Vb of the periodic table or a compound that is under the reaction conditions such oxide forms with substoichiometric amounts Water and then adding an amount of water to the Hydrolysis of the remaining hydrolyzable groups is applied to a substrate and hardened becomes.

Titanium-containing products produced by this process Coatings that have a layer thickness of more than 20 µm have z. B. from a Vickers diamond under 50 g Load not scratched. Show in the "taber abraser test" these coatings after 500 cycles (500 g coating weight) Scattered light losses of around 2%.

These good mechanical properties can usually however, this can only be achieved by multiple coating. Single coatings have a lower scratch resistance and lower abrasion resistance. Furthermore comes with these Coatings the good abrasion resistance in the "taber abraser test" only after a relatively large number of cycles (approx. 200) fully effective.

In these coatings, titanium is replaced by aluminum  (see e.g. DE-OS 38 28 098), so coatings obtained, which is characterized both by high abrasion resistance (1.5% scattered light loss at 500 cycles), as well as through a high weather resistance and corrosion protection award. With these systems, too positive properties, however, usually only with one Bring the multi-layer structure to its full advantage.

An object of the present invention is therefore that known compositions for the production of scratch-resistant Materials based on organofunctional silanes to improve in terms of scratch and abrasion resistance, that values can also be achieved with single coatings can, with the known compositions usually only by one (time and cost intensive) Multiple coating can be obtained.

Furthermore, the procedures outlined above Starting materials are preferred for reasons of accessibility used in the hydrolysis to form lead low-boiling compounds, especially alcohols like methanol and ethanol. As is well known, methanol is one toxic compound that is also a relatively low Flash point. It is therefore desirable that at the hardening of scratch-resistant coatings or moldings as little toxic and highly flammable as possible Hydrolysis products get into the environment.

It is therefore another object of the present invention a process for the production of scratch resistant materials and to provide a suitable composition, which in particular when hardening to a lesser Environmental pollution due to release of toxic and / or light flammable vapors.

Surprisingly, it has now been found that the above objectives  can be realized if one from the known Compositions before application to the substrate or before the molding step, part of the contained therein relatively volatile components by evaporation away. This evaporation unexpectedly affects the Availability of the appropriate composition for a Coating or shaping processes do not, but do nevertheless to the fact that the hardening is less volatile and toxic hydrolysis products get into the atmosphere. Still However, it is more surprising that the removal of a part the volatile hydrolysis products before coating or Shaping to a significant increase in scratching and Abrasion resistance of the resulting products leads.

The subject of the present invention is therefore a Process for the production of scratch-resistant materials which one has a composition that has been obtained by hydrolytic precondensation, if necessary in the presence a condensation catalyst

• a) at least one organofunctional silane of the formula I R ' _m SiX _{(4- m)} (I) in which the groups X, which may be the same or different, are hydrogen, halogen, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or -NR''₂ (R '' = H and / or alkyl) and the radicals R ', which may be the same or different, represent alkyl, alkenyl, alkynyl, aryl, arylalkyl, alkylaryl, arylalkenyl, alkenylaryl, arylalkynyl or alkynylaryl, these radicals being represented by O or S atoms or the group -NR '' may be interrupted and one or more substituents from the group of halogens and the optionally substituted amino, amide, aldehyde, keto, alkylcarbonyl, carboxy, mercapto , Cyano, hydroxyl, alkoxy, alkoxycarbonyl, sulfonic acid, phosphoric acid, acryloxy, methacryloxy, epoxy or vinyl groups and m has the value 1, 2 or 3,
  and / or an oligomer derived therefrom, in an amount of 25 to 95 mol%, based on the total number of moles of the (monomeric) starting components;
• b) at least one compound which is selected from compounds of the empirical formulas II and III AlR₃ (II) MR₄ (III) (M = Ti, Zr) in which the radicals R, which may be the same or different, halogen, alkyl, alkoxy, acyloxy or hydroxyl, where the groups just mentioned can be replaced in whole or in part by chelate ligands,
  and / or an oligomer derived therefrom
  and / or an optionally complexed aluminum salt of an inorganic or organic acid, in an amount of 5 to 75 mol%, based on the total number of moles of the (monomeric) starting components; and if necessary
• c) one or more non-volatile oxides, soluble in the reaction medium, of an element from main groups Ia to Va or subgroups IIb, IIIb, Vb to VIIIb of the periodic table and / or one or more compounds of one of these, which are soluble in the reaction medium and form a non-volatile oxide under the reaction conditions Elements, in an amount of 0 to 70 mol%, based on the total number of moles of the (monomeric) starting components; with an amount of water less than the amount stoichiometrically required to fully hydrolize the hydrolyzable groups, either
  • (i) further condensed by adding further water which wholly or partly effects the hydrolysis of the remaining hydrolyzable groups, and optionally a condensation catalyst, and then applying it to a substrate or subjecting it to a shaping process; and or
  • (ii) applied to a substrate or subjected to a shaping process, condensed further in a water vapor-containing atmosphere;
• and then hardens;

which is characterized in that at the latest before Apply one to the substrate or before shaping Part of the volatile hydrolysis products by evaporation away.

The scratch-resistant manufactured by this process Materials and the corresponding compositions are also subject of the invention.

The following applies to the general formulas given above:
Alkyl residues are e.g. B. straight-chain, branched or cyclic radicals having 1 to 20, preferably 1 to 10, carbon atoms and in particular lower alkyl radicals having 1 to 6, preferably 1 to 4 carbon atoms. Specific examples are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, n-hexyl, dodecyl, octadecyl and cyclohexyl.

Alkenyl residues and alkynyl residues are e.g. B. straight chain, branched or cyclic radicals with 2 to 20, preferably 2 to 10 carbon atoms and at least one C-C double or triple bond and in particular alkenyl radicals and alkynyl radicals such as vinyl, allyl, 2-butenyl, ethynyl and Propargyl.

The alkoxy, acyloxy, alkylamino, dialkylamino, alkylcarbonyl, alkoxycarbonyl, alkylaryl, arylalkyl, alkenylaryl, arylalkenyl, alkynylaryl, arylalkynyl and the substituted amino radicals or amide radicals are derived, for. B. from the above-mentioned alkyl, alkenyl and alkynyl radicals. Specific examples are methoxy, ethoxy, n- and i-propoxy, n-, sec- and tert-butoxy, isobutoxy, b- methoxyethoxy, acetyloxy, propionyloxy, monomethylamino, monoethylamino, dimethylamino, diethylamino, N-ethylanilino, methylcarbonyl, Ethylcarbonyl, methoxycarbonyl, ethoxycarbonyl, benzyl, 2-phenylethyl, tolyl and styryl. Preferred aryl radicals are phenyl, hydroxyphenyl, biphenyl and naphthyl, with phenyl being particularly preferred.

The radicals mentioned can optionally have one or more Wear substituents, e.g. B. halogen atoms, lower alkyl or Alkoxy residues and nitro groups. Here, halogen atoms (e.g. F, Cl, Br), especially fluorine atoms, the final product hydrophobic properties and especially good ones Resistant to condensation, preferably. As have been particularly advantageous in this context halogenated, in particular fluorinated, silanes of the formula I. proven.

Among the halogens that are bound directly to the central atom fluorine, chlorine and bromine are preferred.

The aluminum compounds which can be used according to the invention are those with the empirical formula

AlR₃ (II)

in which the radicals R are the same or different can be halogen, alkyl, alkoxy, acyloxy or hydroxy, with the groups just mentioned partially or completely Chelating ligands can be replaced. The presence of a Chelating ligands are particularly preferred when two or three identical radicals R to a very H₂O lead reactive compound AlR₃ and thereby control the hydrolysis reaction and avoiding precipitation  would complicate. Examples of such radicals R are halogen and alkyl. The use of a is also for R = OH Chelating ligands advantageous. Common chelating ligands are e.g. B. Acetylacetone and ethyl acetoacetate.

Al salts of inorganic and organic acids, such as. B. HNO₃, H₂SO₄, H₃PO₄ and formic acid, acetic acid, propionic acid and oxalic acid can be used according to the invention. In in this case, complexing with is also recommended a chelating ligand.

Concrete examples of usable according to the invention Aluminum compounds are Al (OCH₃) ₃, Al (OC₂H₅) ₃, Al (O-n- C₃H₇) ₃, Al (O-i-C₃H₇) ₃, Al (OC₄H₉) ₃, Al (O-i-C₄H₉) ₃, Al (O-sek.- C₄H₉) ₃, AlCl₃, AlCl (OH) ₂, aluminum formate, aluminum acetate and aluminum oxalate and the corresponding (in part) chelated compounds, e.g. B. the acetylacetonates. At room temperature liquid compounds such. B. Al (O-sec. C₄H₉) ₃ and Al (O-i-C₃H₇) ₃ are particularly preferred.

In the Ti and Zr compounds which can be used according to the invention the general formula (III) applies analogously to the same as for the Al compounds of formula (II).

Specific (and preferred) examples of titanium or Zirconium compounds (b) are TiCl₄, ZrCl₄, Ti (OC₂H₅) ₄, Ti (OC₃H₇) ₄, Ti (O-i-C₃H₇) ₄, Ti (OC₄H₉) ₄, Ti (cresyl) ₄, Zr (O-i-C₃H₇) ₄, Zr (OC₄H₉) ₄, Ti (acetylacetonato) ₂ (O-i-C₃H₇) ₂, Zr (acetylacetonato) ₄, Ti (2-ethylhexoxy) ₄ and other titanium or zirconium complexes with chelating ligands, which preferably have Oxygen and / or nitrogen are coordinated.

According to the invention, it is particularly preferred if the Component (b) at least one aluminum compound of the formula (II) includes, but it is of course also possible  that component (b) consists only of Ti and / or Zr compound (s) consists.

In the case of the organofunctional silanes, the group R ′ optionally by oxygen or sulfur atoms or -NR ′ ′ - groups are interrupted.

Specific examples of suitable organofunctional silanes are:

Some of these silanes are commercial products or leave them produce according to known methods; see. W. Noll, "Chemistry and technology of silicones ", Verlag Chemie GmbH, Weinheim / Bergstrasse (1968).

The index m = 1 is preferably in the silanes of the general formula I. At higher values of m there is a risk that the hardness of the material will decrease if too much such silane is used.

Instead of the monomeric starting silanes can optionally also precondensed oligomers soluble in the reaction medium these silanes are used; d. H. straight chain or Cyclic, low molecular weight partial condensates (Polyorganosiloxanes) with a degree of condensation of e.g. B. about 2 to 100, in particular approximately 2 to 6. The same applies to the aluminum component (b) and component (c). Optionally, the oligomer can also be used which has different central atoms.

As component (c), soluble, non-volatile oxides or such non-volatile oxides forming connections of elements of main groups Ia to Va or subgroups IIb, IIIb, Vb to VIII b of Periodic table used. Preferably, the Component (c) from the following elements: alkaline earth metals, like Mg and Ca; B, Al, Si, Sn, Pb, P, As, Sb, Bi, Cr, Mo, W, Mn, Fe, Co, Ni, Zn and / or V, where B, Si, Sn, Zn and P are particularly preferred. The lanthanide and Actinides can optionally be used.

Among the less volatile oxides are B₂O₃, P₂O₅ and SnO₂ particularly preferred.

Oxides that form low volatility in the reaction medium Connections are e.g. B. inorganic acids such as phosphoric acid and boric acid, and their esters. Furthermore, z. B. Halides such as SiCl₄, HSiCl₃, SnCl₄ and PCl₅, and alkoxides such as Ca (OR) ₂, Si (OR) ₄, Sn (OR) ₄ and VO (OR) ₃, where R of lower alcohols, such as methanol, ethanol, propanol or Butanol. Other starting compounds that can be used are corresponding salts with volatile acids, e.g. B. acetates, such as silicon tetraacetate, basic acetates, such as basic Lead acetate, and formates.  

Preferably used to produce the Composition according to the invention 40 to 90, in particular 40 to 80, and particularly preferably 70 to 80 mol% of the component (a), 10 to 40, especially 10 to 30, and especially preferably 15 to 25 mol% of component (b) and at most 50, in particular at most 40 mol% of component (c).

To produce the composition according to the invention the starting components in the desired mixing ratio with less water than that to complete Hydrolysis of all hydrolyzable groups used pre-condensed stoichiometrically required amount. These substoichiometric amount of water is preferably so added that local over-concentrations and thereby precipitations caused (e.g. Al₂O₃ · xH₂O) avoided will. This can e.g. B. by entering the amount of water in the Reaction mixture with the help of moisture-laden Adsorbents, e.g. B. silica gel or molecular sieves, hydrous organic solvents, e.g. B. 80 percent Ethanol, or salt hydrates, e.g. B. CaCl₂ · 6 H₂O. A another way is the water supply through a system that Contains components that react with each other while doing so release long water, such as this. B. in ester formation from alcohol and acid is the case (ccc = chemically controlled condensation).

The precondensation is preferably carried out in the presence of a Condensation catalyst. If necessary, especially then if one of the components (a) to (c) is highly polar (e.g. a silane with R ′ = aryl), at least one with water partially miscible organic solvent applied be, e.g. B. an aliphatic alcohol, such as ethanol, propanol, Isopropanol or butanol, an ether such as dimethoxyethane Esters such as dimethyl glycol acetate or a ketone such as acetone or methyl ethyl ketone. n-Butanol is used as a solvent prefers. Any added during the precondensation  or solvent formed is preferably not evaporated, but the reaction mixture becomes as such Further condensation used.

Protons or are suitable as condensation catalysts Hydroxyl ion releasing compounds and amines. Specific Examples are organic or inorganic acids, such as Hydrochloric acid, sulfuric acid, phosphoric acid, formic acid or Acetic acid, as well as organic or inorganic bases, such as Ammonia, alkali or alkaline earth metal hydroxides, e.g. B. Sodium, potassium or calcium hydroxide, and in the reaction medium soluble amines, e.g. B. lower alkylamines or alkanolamines. Here are volatile acids and bases, in particular Hydrochloric acid, ammonia and triethylamine, particularly preferred. The total catalyst concentration can e.g. B. up to 3 Mol / liter.

It is particularly advantageous if one of the reaction components (a) to (c) already acts as a condensation catalyst. Here, in particular, the silanes (a) are to be mentioned which have one or more radicals R 'which are linked to basic groups, for. B. -NH₂, are substituted. So z. B. aminoalkylsilanes for these purposes very proven. Specific examples of such compounds are γ- aminopropylsilanes, in particular γ- aminoporpyltri (m) ethoxysilane. The use of such compounds as reaction components has the additional advantage that a decisive improvement in the adhesion of the composition to various substrates, e.g. B. plastic, metal, glass, and at the same time a significant increase in scratch and abrasion resistance can be observed. Such reaction components acting as a condensation catalyst can be used either alone or in combination with the customary condensation catalysts mentioned above.

The precondensation is usually carried out at temperatures of -20 to 100 ° C, preferably at 0 to 30 ° C. At Use of an organic solvent can Pre-condensation even at temperatures up to the boiling temperature of the solvent, but will also be here preferably carried out at 0 to 30 ° C.

If necessary, you can start with one or more Starting components or part of one, several or all Pre-condense the initial components, then the rest Mix in the initial components and then after the Pre-condensation or further condensation processes co-condense.

The subsequent hydrolytic condensation of the Pre-condensate takes place in the presence of further water all or part, e.g. B. at least 80%, in particular at least 90%, the hydrolysis of the remaining hydrolyzable groups. A is preferred Excess water, based on the still existing hydrolyzable groups used. In one out practical reasons preferred embodiment becomes Further condensation the amount of water used for complete hydrolysis of the originally used Starting components would be required stoichiometrically (that water that has already been used remains disregarded).

To avoid precipitation as much as possible, it will particularly preferred, the water addition in several stages, e.g. B. in three stages. In the first Stage z. B. 1/10 to 1/20 of the stoichiometric for hydrolysis required amount of water added. After stirring briefly follows the addition of 1/5 to 1/10 of the stoichiometric amount of water and after another brief stirring, finally one stoichiometric amount of water added, so that at the end there is a slight excess of water.  

The further condensation is preferably carried out in the presence of a of the aforementioned condensation catalysts, wherein also volatile compounds and reaction components (a) are preferred. The total catalyst concentration can e.g. B. up to 5 mol / liter.

In the case of further condensation, one of the organic solvents mentioned above may be present or be added, during the pre and Further condensation formed solvent or for preliminary or Further condensation of any added solvent completed further condensation preferably not evaporated becomes.

The precondensate reacts due to its Hydrolysis sensitivity with water vapor and therefore can also condensed further in an atmosphere containing water vapor will. In this case, all or part of the addition from further water to the condensate can be dispensed with.

The further condensation usually takes place at temperatures from -20 to 100 ° C, preferably 0 to 30 ° C.

At the latest before application to the substrate or before Shaping is obtained from that described above Reaction mixture according to the invention is a part of the volatile Hydrolysis products removed by evaporation.

This evaporation should preferably be done so that the in the condensation products contained in the reaction mixture be subjected to excessive thermal stress. As a result, it will preferred, this evaporation at temperatures not above 40 ° C, especially not above 30 ° C. Especially preferred temperatures are in the range from 0 to 25 ° C. There at atmospheric pressure under such temperature conditions at least most of that in the reaction mixture  existing volatile products by evaporation only bad or cannot be removed at all, this is done Evaporation preferably under reduced pressure, e.g. B. by Use of a water jet vacuum.

According to the invention, it is also preferred that before evaporation already a polar organic in the reaction mixture Solvents with a boiling point in the range of approximately 90 ° C to about 150 ° C, especially about 100 ° C to about 130 ° C. Such solvents are e.g. B. aliphatic alcohols, such as. B. n-propanol, the isomers Butanols, pentanols and hexanols, esters, such as. B. Ethyl acetate, and ketones. A particularly preferred one polar organic solvent is n-butanol.

As already mentioned above, the organic solvent can be present in the reaction mixture right from the start or have been added in the course of the condensation and / or is only added before evaporation. A suitable one Weight ratio of reaction mixture (hydrolysis products plus any water present) to polar organic Solvent is in the range of 2: 1 to 8: 1, especially in the range from 2.5: 1 to 4.5: 1.

The amount of volatile removed by evaporation Components naturally depend on the one hand on whether in the Reaction mixture a polar organic solvent is present or not and on the other hand of it, for what purpose the composition should be used. Is planned to use the composition for coating purposes should be used after the end of the evaporation process Viscosity of the residue is preferably in the range from 20 to 60 mPa · s, in particular in the range from 30 to 45 mPa · s. If the viscosity is too high, the coating becomes a get too large layer thickness, which leads to the fact that  Coating tends to crack and flake off. For The viscosity should be adjusted for coating purposes be that with a simple coating a layer thickness is not over 15 µm results.

For example, with a (particularly preferred) Weight ratio of reaction mixture to solvent from 3 to 3.5: 1 worked, so can be used for coating purposes achieve suitable viscosities of the residue if 20 up to 40% by weight, in particular 30 to 35% by weight, of those present volatile components (volatile hydrolysis products, polar organic solvent and water) removed.

In principle, the evaporation step can already take place if not all water has been added. However, the evaporation is preferably carried out only after addition the total amount of water.

The composition is as such after the evaporation step usable. If necessary, you can use the usual ones Additives are added, such as. B. leveling agents, colorants (Dyes or pigments), UV stabilizers, fillers, Viscosity regulators, lubricants, wetting agents, anti-settling agents or oxidation inhibitors.

Common coating processes are used for coating purposes applied, e.g. B. diving, flooding, pouring, spinning, Spray or spread. According to the Production of coatings is preferred, the However, compositions according to the invention can also be used as such are deformed into objects. To do this, you use yourself usual shaping processes, such as. B. casting, injection molding and extrusion.

Any of them are suitable as substrates for coatings Materials, e.g. B. metals (especially brass and aluminum),  Plastics, ceramics, glass, paper or wood. Even the shape of the Any substrate can be chosen. Particularly advantageous Results are achieved with (scratch-sensitive) plastics, e.g. B. polymethacrylates, polycarbonates, polystyrenes, especially with poly (diethylene glycol bis-allyl carbonate). In general, those produced according to the invention Coatings the substrates u. a. a higher one Wear resistance.

The coating is preferably in layer thicknesses of 5 to 15 µm applied. If necessary, the substrate can Application of the coating according to the invention with a Adhesion promoter or primer layer are primed.

Surface pretreatment is preferred according to the invention of the substrates to be coated by baking (e.g. at PMMA), leaching or exposure to electrical discharge (Corona, low pressure and the like.). Also a halogenation, especially fluorination, the surface can become special when coating plastics as advantageous turn out.

The one applied or subjected to a molding process The composition is then cured by applying it e.g. B. heat treated. A hardening is generally sufficient heating to a few minutes to 1 hour Temperature of up to 200 ° C, preferably 60 to 150 ° C and especially 80 to 130 ° C. About the temperature control at Further condensation and hardening can affect the properties of the Coating or the molded body still to a certain extent can be varied. So you can z. B. First a relative choose low temperature and in a second stage the Increase temperature. Alternatively, you can e.g. B. from the beginning to a temperature at the upper end of the specified ranges heat.  

In the case of coatings, one can Multiple coating done. However, this should be done before Application of the last layer not fully hardened but only partially (e.g. heating for (each) 5 to 15 minutes).

In addition to or instead of heating, e.g. B. also one Curing by radiation (e.g. with an (IR) laser) possible.

If the composition due to use corresponding starting components polymerizable groups contains, the applied layer of lacquer can also be cured photochemically, e.g. B. with UV rays. In this The coating formulation is preferably photoinitiators added. Known photoinitiators for this purpose e.g. B. the under the trademarks Irgacure® and Dorocur® in Commercially available. Otherwise a chemical and / or physical post-treatment of the coating or of the molded body prove to be advantageous. Here would be especially treatment with (high-energy) radiation (UV, laser, IR, microwaves etc.).

Those produced by the process according to the invention scratch-resistant materials stand out in comparison to the materials produced by conventional methods in otherwise same properties in particular by an essential increased scratch and abrasion resistance. Still allowed it the inventive method, about the amount of evaporated volatile products the rheological Properties and viscosity of the composition too check what is especially useful for coating purposes Advantage is. Finally, the method according to the invention also the advantage that when the coating or less toxic vapors into the atmosphere reach.  

The following examples illustrate the present invention. without restricting them.

Example 1

106.3 g of γ- glycidyloxypropyltrimethoxysilane, 11 g of γ- aminopropyltrimethoxysilane, 49.3 g of propyltrimethoxysilane and 49.3 g of aluminum secondary butylate were stirred in a three-necked flask for 5 minutes. Then 3.8 g of distilled water were slowly added dropwise to the mixture while cooling with ice, and the mixture was then stirred for 15 minutes. Then 7.7 g of distilled water were added to the mixture, which was then stirred again for 15 minutes. Finally, 61.5 g of water was added to the mixture, followed by stirring at room temperature for 2 hours.

After the resulting mixture, 36.1 g of n-butanol was added were made using a Rotary evaporator at room temperature (water bath) 50 g (35 % By weight) of a methanol-containing phase in a water jet vacuum deducted. The resulting residue was 0.8 g of one Leveling agent (Dapro U 99) added, whereupon the Composition used in the following coating process has been:

It was 10 × 10 cm large polycarbonate sheets (Makrolon), whose Surface has been pre-treated with a corona discharge was immersed in the above composition and with a Coated speed of 10 cm / min. After a 45 minutes of curing at 130 ° C gave a coating whose properties are shown in Table I.

Example 2

Example 1 was repeated, but only 26% by weight of one Methanol-containing phase were withdrawn. The received Results are also shown in Table I.

Example 3

Example 1 was repeated, but only 15% by weight  deducted on methanol-containing phase. The results are in Table I reproduced.

Comparative example

Example 1 was repeated, except that after the Add the n-butanol without intermediate evaporation Coating was carried out. The results obtained are shown in Table I below.  

Table 1

From the results in Table I it can be seen that the method according to the invention even with a few cycles (100) in the "taber abraser test" to lower stray light losses leads as it with scratch-resistant coatings of the state of the Technology can be achieved. This is also why Interest because in the U.S.A. the quality of a scratch resistant Coating based on the scattered light losses 100 cycles is assessed. The method according to the invention allows simple coatings to be produced, and abrasion resistance with otherwise unchanged properties is as high as the scratch and abrasion resistance more conventional Multiple coatings and therefore does not lead to one insignificant saving of time and material.

Claims (16)

1. A process for the preparation of scratch-resistant materials, in which a composition obtained by hydrolytic precondensation, optionally in the presence of a condensation catalyst, of

• a) at least one organofunctional silane of the formula I R ' _m SiX _{(4- m)} (I) in which the groups X, which may be the same or different, are hydrogen, halogen, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or -NR''₂ (R '' = H and / or alkyl) and the radicals R ', which may be the same or different, represent alkyl, alkenyl, alkynyl, aryl, arylalkyl, alkylaryl, arylalkenyl, alkenylaryl, arylalkynyl or alkynylaryl, these radicals being represented by O or S atoms or the group -NR '' may be interrupted and one or more substituents from the group of halogens and the optionally substituted amino, amide, aldehyde, keto, alkylcarbonyl, carboxy, mercapto , Cyano, hydroxy, alkoxy, alkoxycarbonyl, sulfonic acid, phosphoric acid, acryloxy, methacryloxy, epoxy or vinyl groups and m has the value 1, 2 or 3,
  and / or an oligomer derived therefrom, in an amount of 25 to 95 mol%, based on the total number of moles of the (monomeric) starting components;
• b) at least one compound which is selected from compounds of the empirical formulas II and III AlR₃ (II) MR₄ (III) (M = Ti, Zr) in which the radicals R, which may be the same or different, halogen, alkyl, alkoxy, Mean acyloxy or hydroxy, where the groups just mentioned can be replaced in whole or in part by chelate ligands,
  and / or an oligomer derived therefrom
  and / or an optionally complexed aluminum salt of an inorganic or organic acid, in an amount of 5 to 75 mol%, based on the total number of moles of the (monomeric) starting components; and if necessary
• c) one or more non-volatile oxides, soluble in the reaction medium, of an element of main group Ia to Va or subgroups IIb, IIIb, Vb to VIIIb of the periodic table and / or one or more compounds of one of these which are soluble in the reaction medium and form a non-volatile oxide under the reaction conditions Elements, in an amount of 0 to 70 mol%, based on the total number of moles of the (monomeric) starting components; with an amount of water less than the amount stoichiometrically required to fully hydrolize the hydrolyzable groups, either
  • (i) further condensed by adding further water which wholly or partly effects the hydrolysis of the remaining hydrolyzable groups, and optionally a condensation catalyst, and then applying it to a substrate or subjecting it to a shaping process; and or
  • (ii) applied to a substrate or subjected to a shaping process, condensed further in a water vapor-containing atmosphere;
• and then hardens;

characterized in that some of the volatile hydrolysis products are removed by evaporation at the latest before application to the substrate or before shaping. 2. The method according to claim 1, characterized in that at least some of the radicals X and / or R for methoxy and / or ethoxy. 3. The method according to any one of claims 1 and 2, characterized characterized in that a polar organic solvent with a boiling point in the range from about 90 ° C to about 150 ° C is added. 4. The method according to claim 3, characterized in that the polar organic solvents in an amount of about 50 to about 12.5 wt .-%, based on the weight of the Reaction mixture is added. 5. The method according to any one of claims 3 and 4, characterized characterized in that the polar organic solvent is n-butanol. 6. The method according to any one of claims 1 to 5, characterized characterized in that the evaporation at a temperature up about 40 ° C under reduced pressure. 7. The method according to any one of claims 1 to 6, characterized characterized in that the evaporation after the addition of the all of the water. 8. The method according to any one of claims 1 to 7, characterized characterized that 10 to 50 wt .-% of the total volatile compounds present are deducted. 9. The method according to any one of claims 1 to 8, characterized characterized in that the composition used as a varnish which is applied to a substrate. 10. The method according to claim 9, characterized in that the substrate surface before applying the varnish  treated with a primer, baked out, leached out and / or electrical discharge. 11. The method according to any one of claims 1 to 10, characterized characterized in that the composition by Heat treatment at a temperature up to 200 ° C, preferably 60 to 150 ° C and / or by treatment with Radiation, preferably IR or microwaves, cures. 12. The method according to any one of claims 1 to 11, characterized characterized in that the hardened composition chemically and / or physically, preferably with Laser (UV) radiation, aftertreated. 13. The method according to any one of claims 1 to 12, characterized characterized in that the usual composition Additives, such as leveling agents, colorants, UV stabilizers, fillers, viscosity regulators, Lubricants, wetting agents, anti-settling agents and Oxidation inhibitors, incorporated. 14. Scratch resistant materials, especially with scratch resistant ones Coated substrates, available after Method of one of claims 1 to 13. 15. Composition for the production of scratch-resistant materials, characterized in that it has been obtained by hydrolytic precondensation, optionally in the presence of a condensation catalyst

• a) at least one organofunctional silane of the formula I R ' _m SiX _{(4- m)} (I) in which the groups X, which may be the same or different, are hydrogen, halogen, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or -NR''₂ (R '' = H and / or alkyl) and the radicals R ', which may be the same or different, represent alkyl, alkenyl, alkynyl, aryl, arylalkyl, alkylaryl, arylalkenyl, alkenylaryl, arylalkynyl or alkynylaryl, these radicals being represented by O or S atoms or the group -NR '' can be interrupted and one or more substituents from the group of the halogens and the optionally substituted amino, amide, aldehyde, keto, alkylcarbonyl, carboxy, mercapto , Cyano, hydroxy, alkoxy, alkoxycarbonyl, sulfonic acid, phosphoric acid, acryloxy, methacryloxy, epoxy or vinyl groups, and m has the value 1, 2 or 3,
  and / or an oligomer derived therefrom, in an amount of 25 to 95 mol%, based on the total number of (monomeric) starting components;
• b) at least one compound which is selected from compounds of the empirical formulas II and III AlR₃ (II) MR₄ (III) (M = Ti, Zr) in which the radicals R, which may be the same or different, halogen, alkyl, alkoxy, Mean acyloxy or hydroxy, where the groups just mentioned can be replaced in whole or in part by chelate ligands,
  and / or an oligomer derived therefrom
  and / or an optionally complexed aluminum salt of an inorganic or organic acid, in an amount of 5 to 75 mol%, based on the total number of moles of the (monomeric) starting components; and if necessary
• c) one or more non-volatile oxides, soluble in the reaction medium, of an element of main groups Ia to Va or subgroups IIb, IIIb, Vb to VIIIb of the periodic table and / or one or more compounds of one of these, which are soluble in the reaction medium and form a non-volatile oxide under the reaction conditions Elements, in an amount of 0 to 70 mol%, based on the total number of moles of the (monomeric) starting components; with a quantity of water which is wholly or partly sufficient for the hydrolysis of the hydrolyzable groups present and subsequent evaporation of part of the volatile hydrolysis products present.