MXPA00001979A - Coating compositions with a base consisting of silanes containing epoxide groups - Google Patents

Abstract

The invention relates to a coating composition, comprising at least one silicon compound (A), said compound (A) having at least one radical which cannot be split off hydrolytically, which is directly bonded to Si andwhich contains an epoxide group, a particulate material (B) selected from oxides, oxide hydrates, nitrides and carbides of Si, Al and B and of transition metals, which has a particle size of between 1 and 100 nm, a compound (C) of Si, Ti, Zr, B, Sn or V and at least one hydrolysable compound (D) of Ti, Zr or Al in the following proportions:1 mole of the silicon compound (A), 0.42-0.68 mole of the particulate material (B), 0.28-1.0 mole of the compound (C) and 0.23-0.68 mole of the compound (D).

Description

GOMPOSITIONS OF SILANOS-BASED COATING CONTAINED EPOXIDE PHYRTJPOS. Field of the invention. The present invention relates to coating compositions based on hydrolysable silanes, containing epoxide groups, to the articles coated therewith and to their use. Description of the prior art. It is possible with the help of sol-gel processes to manufacture materials, which are suitable as coatings from alkoxides, for example propanolate or aluminum butanolate, using modified alkoxysilanes. These sol-gel processes are mainly characterized in that the mixture of the starting components is reacted by hydrolysis and condensation processes to give a viscous liquid phase. By means of these synthesis methods, an organically modified inorganic base structure is formed, which has an increased surface area in comparison with the usual organic polymers. A decisive drawback, however, is that due to the high reactivity of the aluminum-containing components, high storage stability (application time) can not be achieved. In comparison with the inorganic materials, the layers obtained are still relatively soft. This is because the inorganic parts certainly have a strongly crosslinking effect in the system but do not contribute to the mechanical properties, such as for example hardness and frictional wear, due to their very small size. By means of the so-called charged polymers, the favorable mechanical properties of the inorganic parts can be fully exploited, since in this case several particle sizes are present.

REF. : 32685 micrometers. Of course, in this case the transparency of the materials is lost and applications in the optics sector are no longer possible. The use of small particles constituted by SiO2 (for example Aerosile *) for the manufacture of transparent layers with high resistance to wear by friction is certainly possible but nevertheless the resistance to wear by friction achievable are similar to those of the aforementioned system, at the low concentrations that can be used. The upper limit of the loading quantities is determined by the high surface reactivity of the small particles, which results in agglomerations or non-tolerable increases in viscosity. WO 95/13326 describes a process for obtaining an organically modified inorganic system, which has a considerably higher hardness compared to that of the systems described above and shows a high optical transparency. In the same way, inorganic systems, organically modified, suitable for protection against corrosion of metal surfaces as well as corresponding systems for hydrophilic coating have been described in said publication. The compositions are obtained according to a process comprising the addition of a material in the form of particles, which is chosen from the oxides, hydrates of oxides, nitrides and carbides of Si, Al, and B or of the transition metals and which has an particle size in the range from 1 to 100 nm, preferably boehmite, and / or a preferably nonionic surfactant and / or an aromatic polyol to at least one silicon compound prehydrolyzed with a residue, which has epoxide groups, directly bonded to the Yes. By the combination of the prehydrolyzed silicon compounds with the particulate material a high scratch resistance is achieved. By combining the prehydrolyzed silicon compound with a surfactant, on the other hand, hydrophilic coatings are obtained, whereas by combining the prehydrolyzed silicon compound with an aromatic polyol, corrosion inhibiting coatings can be obtained. In the procedure can be added, optionally, fluorinated silanes for obtaining hydrophobic or oleophobic coatings, Lewis bases or alcoholates as crosslinking catalysts or other hydrolyzable compounds. DE-40 20 316-A1 discloses a varnish based on hydrolysable silanes, which leads to coatings resistant to frictional wear and flexible after hardening. This can be obtained by the reaction with water of one or more silicon compounds having epoxide groups, the molar ratio between water and the existing hydrolysable groups being from 1: 1 to 0.4: 1. In addition to the silicon compound, other hydrolysable compounds can also be used, for example aluminum, titanium, zirconium, vanadium, tin, lead and boron. Suitable catalysts for the hardening of the composition are tertiary amines, which cause crosslinking of the epoxy groups at temperatures above 60 ° C. DE-OS 30 21 018 discloses a coating mass containing a condensation product, partially hydrolyzed, consisting of alkyltrialkoxysilanes, an organic carboxylic acid and an anionic fluorocarbon surfactant. The silanes used do not contain epoxy groups. The composition provides surface coatings with a surface resistant to frictional wear as well as good transparency, heat stability and adhesion to the base material as well as water resistance. US-5 134 191 discloses a hard coating composition, containing an organic silicon compound, containing epoxy groups, and inorganic submicron particles such as silica sol and which can be cured with a minimum amount of an antimony compound as a catalyst of hardening. This can be used as a coating film for optical articles of synthetic material. If appropriate, the composition can also contain a compound of aluminum. Detailed description of the invention. The object of the present invention is to provide a composition with improved scratch resistance, adhesion, varnish viscosity and elasticity, which has a lower tendency to gelling and turbidity compared to compositions of the state of the art. The technique. This task is solved by means of a coating composition, which comprises at least one silicon compound (A), which has at least one residue which is not dissociable by hydrolysis, is directly bonded to the Si, which contains an epoxide group, a particle form (B), which is chosen from the oxides, the hydrates of the oxides, the nitrides and the carbides of Si, Al, and B as well as of the transition metals and having a particle size in the range from 1 to 100 nm, a compound (C) of Si, Ti, Zr, B, Sn or V and at least one hydrolyzable compound (D) of Ti, Zr or AI, characterized in that it comprises the following proportions 1 mol of the compound of silicon (A), 0.42-0.68 moles of particulate material (B), 0.22-1.0 moles of compound (C) and 0.23-0.68 moles of compound (D) . The compositions according to the invention, characterized by certain quantitative proportions of the components used, provide coatings which are highly resistant to scratching, which adhere particularly well to the coated material and which have a clearly longer application time. In order to achieve a hydrophilic nature of the composition according to the invention, a Lewis base (E) can additionally be used as a catalyst. Additionally, a hydrolysable silicon compound (F) with at least one non-hydrolyzable residue, having from 5 to 30 fluorine atoms bonded directly on carbon atoms, these carbon atoms being separated by at least 2 Si atoms, can be used. The use of a fluorinated silane of this type provides the corresponding coating with additional hydrophobic and dirt repellent properties. Additionally, a preferably nonionic surfactant (G) can be used to obtain hydrophilic properties for a long time and / or an aromatic polyol (H) to achieve corrosion inhibiting properties.

(Increased resistance to condensation water). The compounds (A) are explained in greater detail below (H): Silicon compound (A). The silicon compound (A) consists of a silicon compound having 2 or 3, preferably 3 hydrolyzable residues and 1 or 2, preferably a non-hydrolysable residue. The only non-hydrolysable moiety or at least one of the two non-hydrolysable moieties has an epoxide group. Examples of hydrolyzable moieties are halogen (F, Cl, Br and I, especially Cl and Br), alkoxy (especially alkoxy with 1 to 4 carbon atoms, such as for example methoxy, ethoxy, n-propoxy, i-propoxy and n -butoxy, i-butoxy, sec-butoxy and tert-butoxy), aryloxy (especially aryloxy with 6 to 10 carbon atoms, for example phenoxy), acyloxy (especially acyloxy with 1 to 4 carbon atoms, such as for example acetoxy and propionyloxy) and alkylcarbonyl (for example acetyl). Particularly preferred hydrolysable radicals are alkoxy groups, especially methoxy and ethoxy. Examples of hydrolysable radicals without epoxide groups are hydrogen, alkyl, especially alkyl having 1 to 4 carbon atoms (such as, for example, methyl, ethyl, propyl and butyl), alkenyl (especially alkenyl with 2 to 4 carbon atoms, such as example vinyl, 1-propenyl, 2-propenyl and butenyl), alkynyl, (especially alkinyl with 2 to 4 carbon atoms, such as for example acetylenyl and propargyl) and aryl (especially aryl with 6 to 10 carbon atoms, such as for example phenyl and naphthyl), the groups which have just been mentioned may, if appropriate, have one or more substituents, such as, for example, halogen and alkoxy. Methacryl- and methacryloxy-propyl radicals can also be mentioned in this context. Examples of non-hydrolysable radicals with epoxide groups are especially those which have a glycidii- or glycidyloxy group. Concrete examples of silicon compounds which can be used according to the invention (A) can be seen, for example, on pages 8 and 9 of EP-A-195 493, the disclosure of which is incorporated by reference in the present application. The silicon compounds (A) according to the invention, especially those of the general formula R3SiR 'in which the radicals R are the same or different (preferably identical) and mean a hydrolyzable group (preferably alkoxy with 1 to 4 carbon atoms and especially methoxy and ethoxy) and R 'means a glycidyl- o-glycidyloxy- radical (with 1 to 20 carbon atoms) -alkylene, especially β-glycidyloxyethyl, β-glycidyloxypropyl, d-glycidyloxybutyl, e-glycidyloxypentyl, β-glycidyloxyhexyl, ? -glycidyloxyoctyl,? -glycidyloxynononyl,? -glycidyl-dioxide,? -glycidyloxydecyl and 2- (3,4-epoxycyclohexyl) -ethyl. Due to its easy accessibility, β-glycidyl-oxypropyltrimethoxysilane (hereinafter abbreviated as GPTS) will be particularly preferred according to the invention. Material in the form of particles (B). The particulate material (B) is constituted by an oxide, an oxide hydrate, a nitride or a Si, Al and B carbide as well as transition metals, preferably Ti, Zr and Ce, with a size of particles in the range from 1 to 100, preferably from 2 to 50 nm and more preferably from 5 to 20 nm. This material can be used in the form of a powder, but it will preferably be used in the form of a sol (especially stabilized with acid). Preferred particulate materials are boehmite, CeO2, ZrO2 and TiO2 as well as titanium nitride. The nanoscale particles of boehmite will be especially preferred. The particulate materials can be obtained commercially in the form of powders and in the same way the production of the sols (acid stabilized) is known in the state of the art. In addition, reference can be made in this regard to the examples of obtaining indicated below. The principle of the stabilization of nanoscale titanium nitride by guanidinepropionic acid has been described, for example, in the German patent application P 43 34 639.1.

It is particularly preferable to use boehmite sol in a pH range of 2.5 to 3.5, preferably 2.8 to 3.2, which can be obtained, for example, by suspension of the boehmite powder in HCl. The variation of the nanoscale particles is accompanied, as a rule, by a variation of the refractive index of the corresponding material. Thus, for example, the substitution of boehmite particles for ZrO2 or TiO2 particles leads to materials with higher refractive indices, the refractive index being produced in an additive manner from the volume of the Lorentz-Lorenz equation. of the component with high diffraction and of the matrix. Hydrolyzable compounds (C). In addition to the silicon compounds (A), other hydrolyzable compounds of the group elements formed by Si, Ti, Zr, Al, B, Sn and V and, preferably, hydrolysates are also used to prepare the compositions according to the invention. the or with the silicon compounds (A) The compound (C) is constituted by a compound of Si, Ti, Zr, B, Sn and V of the general formula R * M + 3R'3. * where M means a) If "4, Ti" 4, Zr "4, Sn + 4, or b) Al" 3, B "3 or (VO) +3 where R means a hydrolyzable residue, R 'means a nonhydrolyzable residue and x in the case of tetravalent M metal atoms (case a)) can be from 1 to 4 and in the case of the trivalent M metal atoms (case b)) it can be from 1 to 3. When several R and / or R 'residues are present in the compound (C) these may then be the same or different, preferably x is greater than 1. That is to say that the compound (C) has at least one hydrolyzable radical, preferably several hydrolyzable radicals.

Examples of hydrolyzable moieties are halogen (F, Cl, Br and I, especially Cl and Br), alkoxy (especially alkoxy with 1 to 4 carbon atoms such as for example methoxy, ethoxy, n-propoxy, i-propoxy and n- butoxy, i-butoxy, sec-butoxy or tert-butoxy), aryloxy (especially aryloxy with 6 to 10 carbon atoms, for example phenoxy), acyloxy (especially acyloxy with 1 to 4 carbon atoms, such as for example acetoxy) and propionyloxy) and alkylcarbonyl (for example acetyl). Particularly preferred hydrolysable radicals are alkoxy groups, especially methoxy and ethoxy. Examples of non-hydrolysable radicals are hydrogen, alkyl, especially alkyl having 1 to 4 carbon atoms (such as, for example, methyl, ethyl, propyl and n-butyl, i-butyl, sec.-butyl and tere.-butyl), alkenyl (especially alkenyl with 2 to 4 carbon atoms, such as for example vinyl, 1-propenyl, 2-propenyl and butenyl), alkynyl (especially alkynyl with 2 to 4 carbon atoms, such as for example acetylenyl and propargyl), and aryl, especially aryl with 6 to 10 carbon atoms, such as, for example, phenyl and naphthyl), the groups which have just been mentioned may have one or more substituents, such as, for example, halogen and alkoxy. The methacryl and methacryloxy radicals can also be mentioned in this context. Concrete examples of the compounds (C), which can be used, have been indicated below, however these do not represent any limitation to the compounds (C) that can be used. Si (OCH3) 4, Si (OCH2H5) 4, Si (On or i-C3H7) 4, Si (OC4H9) 4, SiCl4 HSiCl3, Si (OOCCH3) 4, CH3-SiCl3, CH3-Si (OC2H5) 3, C2H5 -SiCl3, C2H5-Si (OC2H5) 3, C3H7-Si (OCH3) 3, C6H5-Si (OCH3) 3, C SÜOOp ^, (CH30) 3-Si-C3H6-Cl, (CH3) 2SiCl2 (CH3) 2Si (OCH3) 2, (CH3) 2Si (OC2H5) 2, (CH3) 2Si (OH) 2, (H ^ SiCl, (C6H5) 2Si (OCH3) 2, (C6H5) 2Si (OC2H5) 2, (i-C3H7 ) 3SiOH, CH2 = CH-Si (OOCCH3) 3, CH2 = CH-SiCl3, CH2 = CH-Si (OCH3) 3, CH2 = CH-Si (OC2H5) 3, CH2 = CH-Si (OC2H4OCH3) 3, CH2 = CH-CH2-Si (OCH3) 3, CH2 = CH-CH2-Si (OC2H5) 3, CH2 = CH-CH2-Si (OOCCH3) 3, CH2 = C (CH3) -COO-C3H7-Si (OCH3) 3, CH2 = C (CH3) -COO-C3H7-Si (OC2H5) 3, Al (OCH3) 3, AKO IL ?, Al (On-C3H7) 3, Al (0-i-C3H7) 3, Al (OC4H9) 3, Al (0-i-C4H9) 3, Al (0-sec. -C4H9) 3, A1Cl3, A1C1 (0H) 2, Al (OC2H4OC4H9) 3, TiCl 4 Ti (OC 2 H 5) 4, Ti (OC 3 H 7) 4, Ti (O-i-C 3 H 7) 4, Ti (OC 4 H <,) 4, Ti (2-ethylhexoxy) 4; ZrCl4, Zr (OC2H5) 4, Zr (OC3H7) 4, Zr (Oi-C3H7) 4, Zr (OC4H9) 4, ZrOCl2, Zr (2-ethylhexoxy) 4, as well as Zr compounds, which have complex-forming residues , such as, for example, the ß-diketone and methacryl challenges, BC13, B (OCH3) 3, B (OC2H5) 3, SnCl4 Sn (OCH3) 4, SNIPOCYIs) ^ VOCI3, VO (OCH3) 3. Particularly preferably, SiR ^ compounds may be used which may be the same or different R moieties and mean a hydrolyzable group, preferably they represent an alkoxy group having 1 to 4 carbon atoms, especially methoxy, ethoxy, n-pro-poxy, i- propoxy, n-butoxy, i-butoxy, sec-butoxy or tert-butoxy. As can be seen, these compounds (C) (especially the silicon compounds) can also have non-hydrolysable residues, which have a double or triple C-C bond. When such compounds are used together with (or even in place of) the silicon compounds (A), they can also incorporate monomers (preferably containing epoxy groups or hydroxyl groups), such as, for example, methacrylates (obviously) into the composition. these monomers may also have difunctional groups or with a functionality greater than 2 of the same type, such as for example poly (meth) acrylates of organic polyols, it is also possible to use organic polyepoxides). During the thermal or photochemically induced hardening of the corresponding composition, in addition to the formation of the organically modified inorganic matrix, a polymerization of the organic species takes place, thereby increasing the density of crosslinking and, therefore, also the hardness of the coatings and the corresponding molded bodies.

Compounds (D). The compound (D) is preferably a compound of Ti, Zr or Al of the following general formula: M (R "') m where M means Ti, Zr or Al and the radicals R'" may be the same or different and mean a hydrolyzable group and n means 4 (M = Ti, Zr) or 3 (M = Al). Examples of hydrolyzable groups are halogen (F, Cl, Br and I, especially Cl and Br), alkoxy (especially alkoxy with 1 to 6 carbon atoms, such as for example methoxy, ethoxy, n-propoxy, i-propoxy, and n-butoxy, i-butoxy, sec-butoxy or tert-butoxy, n-pentyloxy, n-hexyloxy), aryloxy (especially aryloxy with 6 to 10 carbon atoms, for example phenoxy), acyloxy (especially acyloxy with 1) to 4 carbon atoms, such as for example acetoxy and propionyloxy) and alkylcarbonyl (for example acetyl), or an alkoxy group with 1 to 6 carbon atoms-alkyl having 2 to 3 carbon atoms, ie a group derived from alkylene glycol or propylene glycol having 1 to 6 carbon atoms, the alkoxy having the same meaning as that already mentioned above. M is particularly preferably aluminum and R '"means ethanolate, sec-butanolate, n-propanolate or n-butoxyethoxylate Lewis bases (E) The Lewis (E) bases are preferably composed of a nitrogenous compound. Nitrogen compounds can be chosen, for example, from the N-heterocycles, phenols containing amino groups, polycyclic amines and ammonia (preferably in the form of an aqueous solution). Specific examples in this regard are 1-methyl-imidazole, 2- (N, N-dimethylaminomethyl) phenol, 2,4,6-tris (N, N-dimethylaminomethyl) phenol and 1, 8-diazabicyclo [5.4.0] -7-undecene, Among these compounds, 1-methylimidazole is particularly preferred.

Another class of nitrogenous Lewis bases which can be used according to the invention are hydrolysable silanes, which have at least one non-hydrolyzable residue, which comprise at least one primary, secondary or tertiary amino group. Such silanes can be hydrolyzed together with the silicon compound (A) and then represent a Lewis base incorporated into the inorganic, organically modified network. Preferred nitrogen-containing silicon compounds are those of the general formula R3SiR "in which the radicals R are the same or different (preferably identical) and mean a hydrolysable group (preferably alkoxy with 1 to 4 carbon atoms and especially methoxy and ethoxy) ), and R "means a non-hydrolyzable moiety, bonded on Si, comprising at least one primary, secondary or tertiary amino group, Concrete examples of such silanes are 3-antinopropyltrimethoxysilane, 3-amino-propyltriethoxysilane, N- (2-aminoethyl) 3-aminopropyltrime-toxysilane, N- [N '- (2'-aminoethyl) -2-aminoethyl] -3-aminopro-pyrimethoxysilane, N- [3- (triethoxysilyl) propyl] -4,5-dihydroxy-imidazole. The Lewis base is used in the corresponding compositions, in general, in an amount of 0.01 to 0.5 moles per mole of epoxy group of the silicon compound (A), amounts in the range of 0.02 to 0.3 and especially 0.05 to 0.1 mole of Lewis base, per mole of epoxy group Fluorinated compound of silicon (F) Fluorinated, hydrolysable silanes (F), which can be used additionally are those which have less a non-hydrolyzable residue, which has from 5 to 30 fluorine atoms bonded on carbon atoms, which are separated by at least two Si atoms. Such silanes have been described in detail in DE-OS 41 18 184. Concrete examples in this respect are the following: C2F5CH2-CH2-SiY3 n-C6F? 3CH2CH2-SiY3 n-C8F17CH2CH2-SiY3 n-C10F21CH2CH2-SiY3 (Y = OCH3 , O Hj or Cl) i-C3F7O- (CH2) 3-SiCl2 (CH3) n-C6F13CH2CH2SiCl2 (CH3) n-C6FI3CH2CH2SiCl (CH3) 2. Fluorinated silanes are generally used in an amount of 0.1 to , preferably from 0.2 to 10 and more preferably from 0.5 to % by weight, based on the composition. Surfactant (G). The surfactant (G), which can be used to achieve a long-term anti-deposition effect and for a greater hydrophilicity of the coatings, is preferably a non-ionic surfactant. Especially preferred are nonionic surfactants which occur in liquid form at room temperature.

Not only is it possible to use these surfactants during the manufacture of the composition according to the process of the invention, but they can also be incorporated by thermal diffusion subsequently (preferably in aqueous solution) at approximately 50 to 60 ° C. Preferred surfactants are polyoxyethylenelethylethers with variable chain lengths (for example Brij * 92, 96 or 98 from ICI), polyoxyethylene ethers with variable chain lengths (for example Malipal9 24/30 to 24/100 from Hüls and Disponil). 05 from Henkel, sodium lauryl sulfate (for example Sulfopon * 101 Spezial from Henkel), laurylpyridinium chloride (for example Dehyquad C Christ * from Henkel) and polyoxyethylene sorbitan monooleate (for example Tween * from Riedel Haen) The surfactant is generally used in amounts of 1 to 35% by weight, based on the coating composition: Aromatic polyol (H) The aromatic polyol used according to the invention has an average molecular weight of 1,000 or more. Examples of such polyols are, for example, polyphenylene ethers, which carry hydroxy groups on at least two of the phenyl rings, as well as oligomers, in which the aromatic rings by means of a single bond, -O-, -CO-, -SO2- or similarly (and preferably) have two hydroxy groups linked on the aromatic groups. Especially preferred aromatic polyols are aromatic diols. Among these, the compounds of the following general formulas are especially preferred: where X is an alkylene or alkylidene radical (with 1 to 8 carbon atoms), an arylene radical (with 6 to 14 carbon atoms), -O-, -S-, -CO- or -SO2- and n means 0 or 1. Preferably X means alkylene or alkylidene with 1 to 4 carbon atoms, especially means -C (CH3) 2- and -SO2-. The aromatic rings of the compounds can carry, in addition to the OH groups, also up to 3 or 4 further substituents such as, for example, halogen, alkyl and alkoxy. Concrete examples of aromatic polyols (H) which can be used according to the invention are bisphenol A, bisphenol S and 1,5-dihydroxynaphthalene, with bisphenol A being preferred. The polyol (H) will generally be used in such amounts as are present, per mole of epoxy ring of the silicon compound (A), from 0.2 to 1.5 mol, preferably from 0.3 to 1.2 and more preferably from 0.6 to 1.0 mol of hydroxy groups of the aromatic polyol ( H). The use of the silicon compounds (A), which have at least epoxide groups, in the compositions according to the invention leads to coatings and moldings with improved stability to condensation water. Preferably, the compositions according to the invention are obtained by a process described in greater detail below, in which a sol of the material (B) is reacted with a pH in the range of 2.5 to 3.5, preferably from 2.8 to 3.2, with a mixture of the other components. More preferably still, they are prepared by means of a process also defined below, in which the sol, defined as above, is added in two portions to the mixture formed by (A) and (C), preferably maintaining defined temperatures , verifying the addition of (D) between the two portions of (B), also preferably at a certain temperature. It is decisive for the composition according to the invention that the amounts of the components used are within the defined ranges. It has been found that under this precondition, compositions having a scratch resistance can be obtained., a clearly improved adhesion, viscosity of the varnishes, gelling times, turbidity and elasticity. The hydrolyzable silicon compound (A) can be hydrolysed previously in aqueous solution, if appropriate together with the compound (C), using a catalyst (preferably at room temperature), preferably using about 1/2 moles of water per mole of hydrolysable group. . Hydrochloric acid is preferably used as a catalyst for the pre-hydrolysis. The particulate material (B) is preferably suspended in water and the pH is adjusted to 2.5 to 3, preferably to 2.8 to 3.2. Preferably, hydrochloric acid is used for the acidification. When boehmite is used as a particulate material (B), a clear sun will form under these conditions. The compound (C) is mixed with the compound (A). Next, the first portion of the suspended particulate material (B) is added as described above. The amount will preferably be chosen in such a way that the water contained therein is sufficient for the semi-stoichiometric hydrolysis of compounds A) and C). This amount is from 10 to 70% by weight of the total amount, preferably from 20 to 50% by weight. The reaction develops slightly exothermically. After attenuation of the first exothermic reaction, the temperature is established, by heating, at approximately 28 to 35 ° C, preferably approximately 30 to 32 ° C, until the reaction is started and an internal temperature greater than 25 ° is reached. C, preferably greater than 30 ° C, and even more preferably greater than 35 ° C. Once the addition of the first portion of the material (B) is complete, the temperature is maintained for 0.5 to 3 hours, preferably for 1.5 to 2.5 hours, and then cooled to approximately 0 ° C. The remaining material (B) will be added slowly, preferably at a temperature of 0 ° C. Subsequently, the compound (D) and, if appropriate, the Lewis base (E) are also added slowly after the addition of the first portion of the material (B), at approximately 5 0 ° C. The temperature is then maintained, before the addition of the second portion of the material (B), for 0.5 to 3 hours, preferably for 1.5 to 2.5 hours, at approximately 0 ° C. The remaining material (B) is then slowly added at a temperature of about O0. Preferably, the dropwise added solution will be subjected immediately prior to the addition to the reactor or to a pre-cooling to about 10 ° C. After the slow addition of the second portion of the compound (B), at approximately 0 ° C, the cooling is preferably removed so that the heating of the reaction mixture is checked to a temperature higher than 15 ° C (up to the temperature environment) slowly without additional heating.

All temperature indications comprise a deviation from ± 2 ° C. A room temperature of 20 to 23 ° C will be understood as ambient temperature. For the establishment of the rheological properties of the compositions, inert solvents may be added, if appropriate, in any of the steps of the preparation. Preferably these solvents are constituted by liquid alcohols or at room temperature, which are usually also formed during the hydrolysis of the alkoxides preferably used. Particularly preferred alcohols are alcohols with 1 to 8 carbon atoms, especially methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, tert-butanol, n-pentanol, i-pentanol, n- hexanol, n-octanol and n-butoxyethanol. Also preferred are glycol ethers having 1 to 6 carbon atoms, especially n-butoxyethanol.

In addition, the compositions according to the invention may contain customary additives such as, for example, colorants, spreaders, stabilizers with respect to UV, photoinitiators, photosensitizers (in case it is intended to perform a photochemical hardening of the composition) and catalysts for thermal polymerization. The application on the substrate is carried out by means of standard coating processes such as, for example, dipping, brushing, brushing, application by doctor blade, rolling, spraying, application by falling film, coating by rotation and centrifugation. If necessary, a hardening of the coated substrate takes place after previous drying at room temperature. The curing is preferably carried out thermally at temperatures in the range from 50 to 300 ° C, in particular from 70 to 200 ° C, and particularly preferably from 90 to 180 ° C, optionally under reduced pressure. The hardening time must be, under these conditions, less than 200 minutes, preferably less than 100 minutes and even more preferably less than 60 minutes. The thickness of the cured layer should be from 0.5 to 100 μm, especially from 1 to 20 μm and especially from 2 to 10 μm. In the case where unsaturated compounds and photoinitiators are present, hardening can be carried out by irradiation, which can be followed, if necessary, by a final thermal hardening. The choice of materials for the substrate for the coating is not limited. Preferably, the compositions according to the invention are suitable for the coating of wood, textiles, paper, stone articles, metals, glass, ceramics and synthetic materials and in this case especially for the coating of thermoplasts, such as those described in Becker / Braun, Kunststoff-Taschenbuch, Cari Hanser Verlag, München, Vienna 1992. The compositions are very suitable for the coating of transparent thermoplastics and, preferably, of polycarbonates or for the coating of metals or metallized surfaces. In particular, glasses for eyeglasses, optical lenses, automobile windshields and thermal heads can be coated with the compositions obtained according to the invention. The following examples explain the present invention in more detail. Examples Example 1. 244.3 g (1.0 mol) of aluminum tri-sec.-butanolate are added dropwise, with stirring, 354.5 g (3.0 mol) of n-butoxyethanol, with what the temperature increases to approximately 45 ° C. After cooling, the aluminate solution must be kept closed. 1,239 g of 0.1 N HCl were placed. With stirring, 123.9 g (1.92 moles) of Disperal Sol P3 * boehmite were added. It was then stirred for 1 hour at room temperature. The solution was filtered through a deep-bed filter for the separation of the solid impurities. 787.8 g (3.33 mol) of GPTS (β-glycidyloxypropyltrimethoxysilane) and 608.3 g of TEOS (tetraethoxysilane) (2.92 mol) were mixed and stirred for 10 minutes. 214.6 g of boehmite sol were added to this mixture over the course of about 2 minutes. After a few minutes from the addition the sol was heated to about 28 to 30 ° C and was clear approximately after 20 minutes. The mixture was then stirred for about 2 hours at 35 ° C and then cooled to 0 ° C.

Then, at 0 ° C ± 2 ° C, 600.8 g of the solution of Al (OEtOBu) 3, prepared as described above, were added in sec-butanol, which contained 1.0 mole of Al (OEtOBu). )3. Once the addition was complete, stirring was continued for 2 hours at approximately 0 ° C and then the remaining boehmite sol was added at 0 ° C ± 2 ° C. Thereafter, the reaction mixture obtained was heated to room temperature without heating in about 3 hours. As an extender, Byk 306 * was added. The mixture was filtered and the obtained varnish was stored at + 4 ° C. In accordance with this procedure, other examples and comparative examples were carried out, modifying the amounts of the components according to the values indicated in table 1. With the varnishes obtained, test pieces were obtained in the following manner: plates were cleaned with isopropanol. polycarbonate based on bisphenol A (Tg = 147 ° C, Mw 27500) with dimensions of 105 x 150 x 4 mm and received a bottom layer by immersion in a mixture formed by 3% by weight of aminopropyltrimethoxysilane and 97% by weight of butyl glycol with subsequent heat treatment for 0.5 hours at 130 ° C. Subsequently, the plates were respectively coated at an immersion speed V = 100 cm / min with a layer of varnish with a thickness of 20 μm. After cooling for 10 minutes at room temperature, the coated plates were dried for 1 hour at 130 ° C. The thickness of the varnish layer was, after drying, approximately 7 μm. The coated plates were stored, once the final hardening was verified during 2 days at room temperature, and then they were subjected to the tests defined below. The properties of the coatings obtained with these varnishes were determined in the following manner: Grid-shaped cutting test: EN ISO 2409: 1994. The test in the form of a grid after storage in water: 65 ° C, tt = 0/1. The varnished plates are equipped with a grid-shaped cut according to EN ISO 2409: 1994 and stored in hot water at 65 ° C. The storage time (days) is recorded, from which the first loss of adhesion occurs in the Tape test from 0 to 1. Sandblasting test: DIN 52348. Taber abrasion test: DIN friction wear test 52,347; (1,000 cycles, CS10F, 500 g). The results of the evaluation have been represented in the following table: It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Claims (12)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1.- Coating composition comprising at least one silicon compound (A), having at least one non-dissociable residue by hydrolysis, directly linked on Si, which contains an epoxide group, a material in the form of particles (B), which is chosen from oxides, hydrates of oxides, nitrides and carbides of Si, Al, and B as well as metals of transition and having a particle size in the range of 1 to 100 nm, a compound (C) of Si, Ti, Zr, B, Sn or V and at least one hydrolyzable compound (D) of Ti, Zr or A1, characterized in that it comprises the following proportions 1 mole of the silicon compound (A), 0.42-0.68 mole of particulate material (B), 0.22-1.0 mole of compound (C) and 0.23 - 0.68 moles of compound (D). 2. Composition according to claim 1, characterized in that (A) is a compound of the general formula R3SiR 'in which the radicals R are the same or different and mean a hydrolysable group, preferably alkoxy with 1 to 4 carbon atoms and R 'means a glycidyl residue - or a glycidyloxy- radical (with 1 to 20 carbon atoms) - alkylene, (B) is an oxide or an aluminum oxide hydrate, (C) is a compound of the general formula SiR * in that the R moieties are the same or different and mean a hydrolyzable group, preferably an alkoxy group with 1 to 4 carbon atoms, and (D) is a compound of the formula
2. A1R3 in which the radicals R are the same or different and mean a hydrolyzable group, preferably an alkoxy group with 1 to 4 carbon atoms, an alkoxypropanolate group with 1 to 6 carbon atoms or an alkoxyethanolate group with 1 to 6 carbon atoms .
3. 3. -G3ipryrictión according to the iCR iir n 1 or 2, fall fer rip because (A) is? Glycidyloxypropylsilane, (B) is a boehmite sol with a particle size in the range of 1 to 100 nm, (C) ) is tetraethoxysilane and (D) is A (bu-toxietanolate) 3.
4. 4.- Csrposic-l? N according to ina of the reivirr} if? rpptes 1 to 3, saracbadzada arμ? further comprises a Lewis base (E) and / or at least one hydrolysable silicon compound (F), having at least one non-hydrolyzable residue, having from 5 to 30 fluorine atoms bonded directly on carbon atoms, which are separated by at least 2 Si atoms, and / or a surfactant (G) and / or an aromatic polyol (H) with an average molecular weight not greater than 1,000.
5. 5. Composition according to one of claims 1 to 4, characterized in that a sol of the material in the form of particles (B) is reacted with a pH in the range of 2.5 to 3.5, with a mixture constituted by the compound of silicon (A) and the compound (C) as well as the compound (D) and, if appropriate, the other components (E) to (H).
6. 6. Composition according to claim 5, characterized in that the silicon compound (A) and the compound (C) are previously mixed, then a) a first portion of 10 to 70% by weight of the amount of the compound is added. sol of the material (B) with a pH of 2.5 to 3.5, then b) compound (D) is added and again c) the second portion of the sol of the material (B) is added.
7. 7. Composition according to claim 6, characterized in that the addition in step a) is carried out at a temperature of> 100. 25 ° C and the addition in step b) and in step c) is carried out at 0 ± 2 ° C.
8. 8 .- CbirxFdción according to the dc-Tes 6 or 7, chalked-perca perqué hydr Liza pceviaiHite cempuesto (A) if necessary together with the a-ppussto (C) san cp lor »rfc»? t? ICT.
9. 9. - Composition according to claims 6, 7 or 8, sara-? Ad-zad? because acid cQca ± -drd D dl ii? b is used for pH adjustment.
10. 10. Use of the composition according to one or more of claims 1 to 9, for the coating of substrate materials of any type, preferably of thermoplastic, especially of polycarbonates.
11. 11. Use according to claim 10, characterized in that a composition containing, if appropriate, an inert solvent, preferably an alcohol with 1 to 8 carbon atoms and / or monoalkyl glycol ether, especially n-butoxy, is applied to the surface of the substrate. ethanol, to adjust the rheological properties and (a) is thermally hardened preferentially at temperatures of 90 to 180 ° C or (b) hardens in a photochemical manner, after the previous addition of a photoinitiator and, if necessary, is subjected to to a final thermal hardening.
12. 12. Articles coated with a composition obtained according to one or more of the claims 1 to 9, especially slow, glasses for glasses, windscreens for glass or synthetic vehicles, preferably polycarbonates, and metallic thermal heads. rnivTPOSTCT N D P EPOXID GROUPS CONTINUE. SUMMARY OF THE INVENTION The object of the present invention is a coating composition, comprising at least one silicon compound (A), having at least one non-dissociable residue by hydrolysis, linked directly on Si, containing an epoxide group, a material in the form of particles (B), which is chosen from oxides, oxide hydrates, nitrides and Si, Al and B carbides as well as transition metals and which has a particle size in the range from 1 to 100 nm, a compound (C) of Si, Ti, Zr, B, Sn or V and at least one hydrolysable compound (D) of Ti, Zr or Al, comprising the following proportions: 1 mole of composed of silicon (A), 0.42-0.68 moles of particulate material (B), 0.28-1.0 moles of compound (C) and 0.23-0.68 moles of compound ( D).