Nanostructured moulded bodies and layers and method for producing same

NANOSTRUCTURED MOLDED BODIES AND LAYERS AND METHOD FOR THE PRODUCTION THEREOF

0002The present invention relates to nanostructured moldings and layers and to processes for their production. In particular, the present invention relates to nanostructured moldings and layers which are produced with the aid of a wet chemical process.

0003Nanostructured materials have been known for a long time. They are usually produced by compacting nanoscale particles with diameters in the lower nanometer range using a suitable method (see, for example, H. Gleiter, Nanocrystalline Materials, Pergamon Press, Oxford, 1989). This usually happens under high pressure. Here, the high diffusion rates in the outer regions of the nanoscale particles are exploited, whereby compression into dense bodies takes place under the influence of pressure (and under certain circumstances simultaneous exposure to elevated temperatures). Corresponding wet-chemical processes, such as the sol-gel process, generally lead to porous gels, since the high surface activity of the particles causes them to bind, but the particles are not closely lined up and the gussets are not filled. Materials manufactured using such processes are uniform, ie they have interfacial phases, the composition of which does not differ (significantly) from that of the particle phase (only the gas phase of the environment can also be present).

0004It has now surprisingly been found that when the nanoscale particles are provided with polymerizable and / or polycondensable organic surface groups and these surface groups are polymerized and / or polycondensed, nanostructured material systems are accessible by wet chemical means, which are on a par with the systems previously produced in a dry way or are even superior. In particular, highly transparent materials are also accessible in this way, since the correlation lengths for the Raleigh scattering are not achieved due to the small distances between the particles (one to a few nm). The present invention thus relates to a process for the production of nanostructured moldings and layers, which comprises the following stages:

0005a) Provision of a nanoscale inorganic solid particles with polymerizable and / or polycondensable organic

0006Flowable mass containing surface groups; b1) inserting the mass from step a) into a mold; or b2) applying the mass from step a) to a substrate; c) polymerization and / or polycondensation of the organic

0007Surface groups of the inorganic solid particles to form a hardened shaped body or a hardened layer.

0008In many cases it can be advantageous if the above step c) is followed by a thermal aftertreatment, preferably at a temperature in the range from 60 to 150 ° C., in particular 80 to 130 ° C., of the hardened shaped body or the hardened layer .

0009Alternatively or additionally, (further) thermal compression of the shaped body or of the layer can take place at a temperature of at least 250 ° C., preferably at least 400 ° C., and in particular at least 500 ° C. In the case of a layer on a substrate, this thermal compaction can of course only be carried out if the substrate material can withstand such high temperatures without impairment, as is the case, for example, with glass and many metals or Metal alloys (but also some plastics) is the case.

0010In some cases it may also be advisable to carry out (further) thermal compression at temperatures in the range from 800 to 1500 ° C., preferably 1000 to 1400 ° C.

0011In general, a (post) treatment at temperatures of at least 350 ° C. enables the nanoscale inorganic solid particles to be used as a mechanically solid precursor for the production of a purely inorganic solid.

0012In the present description and the appended claims, “nanoscale inorganic solid particles” are intended to mean those with an average particle size (an average particle diameter) of not more than 200 nm, preferably not more than 100 nm, and in particular not more than 70 nm. A particularly preferred particle size range is 5 to 50 nm.

0013The nanoscale inorganic solid particles can consist of any materials, but they preferably consist of metals and in particular of metal compounds such as (optionally hydrated) oxides such as ZnO, CdO, Si0₂, Ti0₂, Zr0₂, Ce0₂, Sn0₂, Al₂0₃, ln₂0₃, La₂0₃, Fe₂0₃, Cu₂0, Ta₂0₅, Nb₂0₅, V₂0₅, Mo0₃ or W0₃; Chalcogenides such as sulfides (e.g. CdS, ZnS, PbS and Ag₂S), selenides (e.g. GaSe, CdSe and ZnSe) and tellurides (e.g. ZnTe or CdTe), halides such as AgCI, AgBr, Agl, CuCI, CuBr, Cdl₂ and pbl₂; Carbides such as CdC₂ or SiC; Arsenides such as AlAs, GaAs and GeAs; Antimonides such as InSb; Nitrides such as BN, AIN, Si₃N₄ and Ti₃N₄; Phosphides such as GaP, InP, Zn₃P₂ and Cd₃P₂; Phosphates, silicates, zirconates, aluminates, stannates and the corresponding mixed oxides (e.g. those with a perovskite structure such as BaTi0₃ and PbTi0₃).

0014The nanoscale inorganic solid particles used in stage a) of the process according to the invention are preferably those of oxides, sulfides, selenides and tellurides of metals and mixtures thereof. Nanoscale particles of SiO are particularly preferred according to the invention₂, Ti0₂, Zr0₂, ZnO, Ta₂0₅, Sn0₂ and Al₂0₃ (in all modifications, especially as boehmite, AIO (OH)) and mixtures thereof.

0015Since the nanoscale particles which can be used according to the invention cover a wide range of refractive indices, the refractive index of a shaped body or a layer can be conveniently adjusted to the desired value by suitable selection of these nanoscale particles.

0016The nanoscale solid particles used according to the invention can be produced in a customary manner, for example by flame pyrolysis, plasma processes, gas phase condensation processes, colloid techniques, precipitation processes, sol-gel processes, controlled nucleation and growth processes, MOCVD processes and (micro) emulsion processes. These methods are described in detail in the literature. In particular, for example Metals (for example after the reduction of the precipitation process), ceramic oxidic systems (by precipitation from solution), but also salt-like or multi-component systems can be used. The salt-like or multicomponent systems also include semiconductor systems.

0017The production of the nanoscale inorganic solid particles provided with polymerizable and / or polycondensable organic surface groups, which are used according to the invention, can in principle be carried out in two different ways, namely on the one hand by surface modification of already produced nanoscale inorganic solid particles and on the other hand by producing these inorganic nanoscale solid particles using one or more compounds which have such polymerizable and / or polycondensable groupings. These two approaches are explained in more detail below and in the examples.

0018The organic polymerizable and / or polycondensable surface groups can be any groups known to the person skilled in the art, which undergo radical, cationic or anionic, thermal or photochemical polymerization or thermal or photochemical polycondensation (if appropriate in the presence of a suitable initiator or catalyst) are accessible. Surface groups which have a (meth) acrylic, allyl, vinyl or epoxy group are preferred according to the invention, with (meth) acrylic and epoxy groups being particularly preferred. Among the groups capable of polycondensation, hydroxyl, carboxy and amino groups should be mentioned, with the aid of which ether, ester and amide bonds can be obtained between the nanoscale particles.

0019It is also preferred according to the invention that the organic groups present on the surfaces of the nanoscale particles, which comprise the polymerizable and / or polycondensable groups, have a relatively low molecular weight. In particular, the molecular weight of the (purely organic) groupings should not exceed 500 and preferably 300, particularly preferably 200. Of course, this does not exclude a significantly higher molecular weight of the compounds (molecules) comprising these groupings (for example 1000 and more).

0020As already mentioned above, the polymerizable / polycondensable surface groups can in pr inciple be provided in two ways. If a surface modification of nanoscale particles that have already been produced is carried out, all (preferably low molecular weight) compounds are suitable for this purpose which, on the one hand, have one or more groups which have (functional) groups (such as , for example, OH groups) on the surface of the nanoscale solid particles in the case of oxides) can react or at least interact, and on the other hand have at least one polymerizable / polycondensable group. Thus, the corresponding compounds can, for example, form both covalent and ionic (salt-like) or coordinative (complex) bonds to the surface of the nanoscale solid particles, while dipole-dipole interactions, hydrogen bonds and van der Waals interactions should be mentioned among the pure interactions. The formation of covalent and / or coordinative bonds is preferred. Specific examples of organic compounds which can be used to modify the surface of the nanoscale inorganic solid particles are, for example, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, β-dicarbonyl compounds (for example β-diketones or β-carbonylcarboxylic acids) with polymerizable double bonds, ethylenically unsaturated alcohols and amines, epoxides and the like. According to the invention, particularly preferred as such compounds are - in particular in the case of oxidic particles - hydrolytically condensable silanes with at least (and preferably) one non-hydrolyzable radical which has a polymerizable carbon-carbon double bond or an epoxy ring. Such silanes preferably have the general formula (I):

0021XR¹-SiR²₃ (I) where X is CH₂= CR³-COO, CH₂= CH or glycidyloxy, R³ Represents hydrogen or methyl, R¹ is a divalent hydrocarbon radical having 1 to 10, preferably 1 to 6 carbon atoms, which optionally contains one or more heteroatom groups (for example O, S, NH) which separate adjacent carbon atoms, and the radicals R², identical or different from one another, are selected from alkoxy, aryloxy, acyloxy and alkylcarbonyl groups and halogen atoms (in particular F, Cl and / or Br).

0022The groups R are preferably² identical and selected from halogen atoms, C ^ alkoxy groups (eg methoxy, ethoxy, n-propoxy, i-propoxy and butoxy), C₆.₁₀- Aryloxy groups (e.g. phenoxy), C ^ -acyloxy groups (e.g. acetoxy and propionyloxy) and C₂.₁₀-Alkylcarbonyl groups (e.g. acetyl).

0023Particularly preferred radicals R² are C ^ alkoxy groups and especially methoxy and ethoxy.

0024With the rest R¹ it is preferably an alkylene group, in particular one having 1 to 6 carbon atoms, such as ethylene, propylene, butylene and hexylene. If X for CH₂= CH stands for R¹ preferably methylene and in this case can also mean a mere bond.

0025X is preferably CH₂= CR³-COO (where R³ preferably CH₃ is) or glycidyloxy. Accordingly, particularly preferred silanes of the general formula (I) are (meth) acryloyloxyalkyltrialkoxysilanes such as 3-methacryloyloxypropyltri (m) ethoxysilane and glycidyloxyalkyltrialkoxysilanes such as 3-glycidyloxypropyltri (m) ethoxysilane. If the nanoscale inorganic solid particles are already produced using one or more compounds which have polymerizable / polycondensable groups, a subsequent surface modification can be dispensed with (although this is of course possible as an additional measure).

0026The in situ production of nanoscale inorganic solid particles with polymerizable / polycondensable surface groups is shown below using the example of Si0₂-Particles explained. For this purpose the Si0₂Particles can be produced, for example, by the sol-gel process using at least one hydrolytically polycondensable silane with at least one polymerizable / polycondensable group. Suitable silanes of this type are, for example, the silanes of the general formula (I) already described above. These silanes are preferably used either alone or in combination with a suitable silane of the general formula (II)

0027SiR²₄ (II) wherein R² has the meaning given above. Preferred silanes of the general formula (II) above are tetramethoxysilane and tetraethoxysilane.

0028Of course, it is also possible, in addition or as an alternative to the silanes of the general formula (II), to use other silanes, for example those which have a (non-hydrolyzable) hydrocarbon group without any functional group, such as, for example, methyl- or phenyltrialkoxysilanes. In particular, if an easy-to-clean surface of the shaped body or the layer is desired, it may be advisable to add a certain amount (for example, to. In addition to the silanes of the general formula (I) and, if appropriate, the general formula (II) 60 and in particular up to 50 mole percent, based on all the silanes used), use silanes with fluorine-containing (non-hydrolyzable) residues, in particular hydrocarbon residues. Silanes of the above formula (I) in which R² as defined above, R¹ represents an ethylene group and X represents a perfium alkyl group having 2 to 12, preferably 4 to 8, carbon atoms. Further silanes which can be used for this purpose are, for example, those with (per) fluorinated aryl (in particular phenyl) groups. Of course, such fluorinated silanes can also be used for surface modification of already finished nanoscale inorganic solid particles.

0029The material used in stage a) of the process according to the invention is in the form of a still free-flowing mass (suspension). The liquid constituent of this composition consists, for example, of water and / or (preferably water-miscible) organic solvents and / or compounds which were used or produced in the course of the production of the nanoscale particles or their surface modification (for example alcohols in the case of alkoxysilanes) , together. Suitable organic solvents optionally used are, for example, alcohols, ethers, ketones, esters, amides and the like. However, an (additional) constituent of the flowable composition can also be, for example, at least one monomeric or oligomeric species which has at least one group which can react (polymerize or polycondense) with the polymerizable / polycondensable groups present on the surface of the nanoscale particles. Examples of such species are monomers with a polymerizable double bond, such as, for example, acrylic acid esters, methacrylic acid esters, styrene, vinyl acetate and vinyl chloride. As (preferably used) monomeric compounds with more than one polymerizable bond, those of the general formula (III) may be mentioned in particular:

0030(CH₂= CR³-COZ-)_n-A (IM) where n = 2, 3 or 4, preferably 2 or 3 and in particular 2; Z = O or NH, preferably O; R = H, CH₃;

0031A = n-valent hydrocarbon radical with 2 to 30, in particular 2 to 20, carbon atoms, which may have one or more heteroatom groups which are each located between two adjacent carbon atoms (examples of such heteroatom groups are O, S, NH, NR (R = hydrocarbon radical ), preferably O). Furthermore, the hydrocarbon radical A can carry one or more substituents, which are preferably selected from halogen (in particular F, Cl and / or Br), alkoxy (in particular C 1-4 alkoxy), hydroxy, optionally substituted amino, N0₂, OCOR⁵, COR⁵ (R⁵ = C ^ alkyl or phenyl). However, the radical A is preferably unsubstituted or substituted with halogen and / or hydroxy.

0032In a particularly preferred embodiment of the present invention, A is derived from an aliphatic diol, an alkylene glycol, a polyalkylene glycol or an optionally alkoxylated (eg ethoxylated) bisphenol (eg bisphenol A).

0033Further usable compounds with more than one double bond are, for example, allyl (meth) acrylate, divinylbenzene and diallyl phthalate. It is also possible, for example, to use a compound having 2 or more epoxy groups (in the case where epoxy-containing surface groups are used), for example bisphenol A diglycidyl ether or also an (oligomeric) precondensate of a hydrolyzable silane containing epoxy groups (for example glycidoxypropyltrimethoxysilane).

0034If additional monomeric compounds with polymerizable / polycondensable groups are used, their proportion preferably makes up not more than 40% by weight, in particular not more than 30 and particularly preferably not more than 15% by weight, of the total solids content of the flowable mass of stage a) off.

0035In stage b) of the process according to the invention, the flowable composition from stage a) is either introduced into a suitable mold in order to produce a shaped body or applied to a desired substrate in order to coat the substrate in whole or in part. The coating methods suitable for this purpose are the conventional ones known to the person skilled in the art. Examples include dipping, spraying, knife coating, brushing, brushing, spinning, etc. Before being introduced into the mold or When applied to the substrate, the flowable mass can be adjusted to a suitable viscosity, for example by adding solvent or evaporating volatile constituents (in particular solvent already present).

0036Substrates made of any materials, in particular plastics, metal and glass, are suitable for coating with the flowable mass of stage a) of the process according to the invention. These substrate materials can optionally be subjected to a surface treatment (for example degreasing, roughening, corona discharge, treatment with a primer, etc.) before the flowable composition is applied. In particular in the case of coating plastic substrates, suitable adhesion can be provided by adding a suitable monomeric polymerizable compound and / or according to the preferred embodiment described in more detail below.

0037Examples of metals that can be coated according to the invention include metals such as aluminum, copper, zinc, nickel and chromium and metal alloys such as (stainless steel), brass and bronze. Suitable plastic substrates are, for example, those made of polycarbonate, polyesters, polyamides, polystyrene, poly (meth) acrylates (e.g. Polymethyl methacrylate), PVC, polyolefins (such as polyethylene and polypropylene), rubbers (ABS, NBS, etc.) and polyphenylene sulfide, to name but a few.

0038In step c) of the process according to the invention, a polymerization and / or polycondensation of the polymerizable / polycondensable surface groups of the nanoscale inorganic solid particles (and optionally the polymerizable / polycondensable groups of the additionally used monomeric or oligomeric species) is carried out. This polymerization / polycondensation can be carried out in the manner familiar to experts. Examples of suitable processes are thermal, photochemical (for example with UV radiation), electron beam curing, laser curing, room temperature curing etc. If appropriate, such a polymerization / polycondensation takes place in the presence of a suitable catalyst or starter (initiator), which is the flowable mass of stage a) is added at the latest immediately before they are introduced into the mold or applied to the substrate.

0039Suitable starters / starter systems are all common starters / starter systems known to those skilled in the art, including radical photo starters, radical thermal starters, cationic photo starters, cationic thermal starters and any combination thereof.

0040Specific examples of radical photo starters that can be used are Irgacure^® 184 (1-hydroxycyclohexylphenyl ketone), Irgacure^® 500 (1-hydroxycyclohexylphenyl ketone, benzophenone) and other photo initiators from Irgacure available from Ciba-Geigy^®-Type; Darocur^® 1173, 1116, 1398, 1174 and 1020 (available from Merck); Benzophenone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, benzoin, 4,4'-dimethoxybenzoin, benzoin ethyl ether, benzoin isopropyl ether, benzil dimethyl ketal, 1, 1, 1-trichloroacetophenone, diethoxyacetophenone and dibenzosuberone.

0041Examples of radical thermal starters include organic peroxides in the form of diacyl peroxides, peroxydicarbonates, alkyl peresters, alkyl peroxides, perketals, ketone peroxides and alkyl hydroperoxides and azo compounds. Dibenzoyl peroxide, tert-butyl perbenzoate and azobisisobutyronitrile should be mentioned as specific examples.

0042An example of a cationic photo starter is Cyracure^® UVI-6974, while a preferred cationic thermal starter is 1-methylimidazole.

0043These starters are used in the usual amounts known to the person skilled in the art (preferably 0.01-5% by weight, in particular 0.1-2% by weight, based on the total solids content of the flowable mass from stage a)). Of course, the starter can be completely dispensed with under certain circumstances, such as in the case of electron beam or laser curing. The polymerization / polycondensation of stage c) of the process according to the invention is preferably carried out thermally or by irradiation (in particular with UV light). Photochemical polymerization / polycondensation or a combination of thermal and photochemical polymerization / polycondensation is particularly preferred.

0044The polymerisation / polycondensation can be preceded by the removal of further volatile, non-polymerizable / non-polycondensable compounds from the composition in the mold or on the substrate. However, this removal of volatile constituents can also or additionally take place at the stage of the polymerization / polycondensation or afterwards.

0045In the following, a typical method according to the invention, which can lead to transparent moldings, is to be outlined by way of example, the value ranges and procedures given being of general validity irrespective of the materials actually used.

0046Nanoscale particles made of Si0, for example₂, Ti0₂, Zr0₂ or other oxidic or sulfidic materials (particle size 30 to 100 nm, preferably 40 to 70 nm) are in a solvent (for example in a lower alcohol such as methanol, ethanol, propanol) in a concentration of 1 to 20 wt .-%, preferably 5 up to 15% by weight, dispersed and with a surface modifier with polymerizable / polycondensable groups in an amount of preferably 2 to 25% by weight, in particular 4 to 15% by weight (based on the total solids content). The surface modification can be carried out by stirring for several hours at room temperature when using, for example, silanes. If necessary, a monomeric or oligomeric material with polymerizable / polycondensable groups can then be added to the surface modifier or is compatible with the surface groups, in an amount of, for example, up to 20% by weight, preferably 4 to 15% by weight (based on the total solids content). After adding one or more suitable starters (each in an amount of, for example, 0.01 to 1% by weight, preferably 0.1 to 0.5% by weight, based on the total solids content), the solvent is partially removed ( preferably 50 to 98, in particular 75 to 95%). The still flowable mass is then given the desired shape, which is followed by the removal of the remaining solvent. A first hardening is then carried out. A photopolymerization is preferably used to reduce the reaction times; any light sources, in particular UV light emitting sources, can be used here (for example mercury vapor lamps, xenon lamps, laser light, etc.). The curing with laser light allows an application for the so-called "rapid prototyping". After thermal post-curing for further densification of the structure (for example 0.5 - 4 hours at 70 to 150 ° C, preferably 1 - 2 hours at 80 to 100 ° C), a green body is obtained. This green body can, for example, within 2 to 10 hours, preferably 3 to 5 hours, to a temperature of, for example 500 ° C heated and kept for example 2 to 10 hours (preferably 3 to 5 hours) at this temperature. In most cases, this step leads to the complete loss of the organic (carbon-containing) groupings in the shaped body. For the final compression, the molded body can then, for example, within 2nd up to 10 hours (preferably 3 to 5 hours) heated to a temperature of, for example, 1400 ° C. and, for example, 1 to 5 hours (preferably 2 to 3 hours) kept at this temperature. A colorless, transparent, purely inorganic molded body can be obtained in this way.

0047For layer production, for example, the procedure can be such that hydrolyzable silanes with polymerizable / polycondensable groups in a concentration of preferably not more than 100% by weight, in particular not more than 75% by weight (based on nanoparticles), to sols with, for example, oxidic or sulfidic nanoparticles. After adjusting the viscosity by adding or removing solvent (e.g. alcohol) and after adding a photoinitiator (e.g. in a concentration of 5% by weight, based on the silane used), curing the layer on the selected substrate with preferably UV light leads to transparent, crack-free and homogeneous layers. A thermal aftertreatment at, for example, 60 to 100 ° C. generally leads to a significant improvement in the layer properties, but is not essential. The layers produced in this way have good abrasion resistance. Since the thermal aftertreatment can be carried out at relatively low temperatures in this process, substrates with low thermal stability can also be used without problems. As already mentioned above, by varying the amount and type of silane used and by adding an additional organic monomer (methacrylates, acrylates, etc.) in low concentrations (for example <5% by weight), it is possible to adhere to the layer's adhesive properties adapt the substrate so that, for example, glass and plastics can be coated equally. Furthermore, the use of the above-mentioned fluorinated silanes in the surface modification leads to easy-to-clean layers on the corresponding substrates or a reduction in the surface energy, while the addition of, for example, surfactants can increase the surface energy.

0048In particular for the coating of plastic substrates, a preferred embodiment of the present invention is used in such a way that nanoparticles (in particular those of AIOOH, Zr0₂, Ti0₂ and the like) in a relatively high concentration (generally at least 15 and preferably at least 20% by weight or at least 7 or 10% by volume, with preferred upper limits at 80% by weight, in particular 60% by weight, or 40 vol%, in particular 25 vol%) dispersed in a liquid system which, as an essential constituent, contains at least one hydrolyzable silane with a polymerizable / polycondensable group (e.g. one of the above general formula (I)), and then carries out a (usual) pre-hydrolysis of the silane. In addition to the silane with a polymerizable / polycondensable group, other hydrolyzable components may also be present, in particular other (optionally fluorinated) silanes (e.g. those of the general formula (II) above) and / or hydrolyzable compounds (e.g. alkoxides, halides) of main and subgroup metals (e.g. AI, Ti, Zr). After the pre-hydrolysis, further species with more than one (preferably two) copolymerizable / copolycondisable groups (in particular those of the general formula (III) above, preferably in amounts of up to 40, in particular up to 30 and particularly preferably up to 15, by weight .-%) are added. (Meth) acrylate groups are particularly preferred as polymerizable groups. Before applying it to a plastic substrate, this system can still have a solvent (e.g. an alcohol) can be added to adjust the viscosity, as well as conventional paint additives (see below). Surprisingly, although the resulting lacquer can be cured thermally (preferably after adding an appropriate thermostarter), when using a photoinitiator (preferably in the usual amounts indicated above), (sole) photochemical curing (preferably with UV light) also increases a highly scratch-resistant, transparent layer that also adheres well to most plastic substrates without pretreating their surfaces (e.g. in the case of polycarbonates, polystyrene, poly (meth) acrylate, etc.).

0049Of course, dyes, pigments, matting agents, etc. can also be added to the corresponding coating composition if a colored or non-transparent layer is desired. Examples of other common additives for compositions of the type described are flow additives, UV absorbers, antioxidants (for example HALS), antistatic agents, surfactants (for hydrophilic surfaces) and fluorinated compounds (for hydrophobic / oleophobic surfaces).

0050An additional advantage of the procedure just described is that since the process is preferably carried out without a separately added solvent (except for the purpose of adjusting the viscosity after the pre-hydrolysis), a solvent exchange, which is often described in the prior art, is not necessary before the application.

0051The moldings accessible according to the invention are suitable for a large number of applications. In this context, the following fields of application may be mentioned merely by way of example: rapid prototyping, for example in medical technology (for prostheses, organ simulation), prototyping in the automotive sector (design models, engine components, etc.), optical components, tool development, test procedure development. In the case of the layers according to the invention, scratch-resistant coatings with functional properties (antireflection, corrosion protection, hydrophilicity, hydrophobicity, antistatic layers) should generally be mentioned. Coatable materials include, but are not limited to, those made of transparent and non-transparent plastics, glass, metals, stone, wood, paper and textiles.

0052The present coating compositions are particularly suitable for coating buildings and parts thereof; Means of transportation and parts thereof; Work equipment, devices and machines for commercial or industrial purposes and research and parts thereof; Household items and work equipment for the household and parts thereof; Equipment, devices and aids for games, sports and leisure and parts thereof; as well as devices, aids and devices for medical purposes and the sick. These compositions are also very suitable for producing interference layers. Specific examples of materials or objects that can be coated are given below:

0053Buildings (especially buildings) and parts thereof:

0054Interior and exterior facades of buildings, floors and stairs made of natural stone, concrete etc., plastic floor coverings, carpets and carpets, skirting boards (rubbing strakes), windows (in particular window frames, window sills, glass or plastic glazing and window handles), blinds, roller blinds, Doors, door handles, fittings in the kitchen, bathroom and toilet, shower cubicles, sanitary cells, toilet cubicles, pipes, radiators, mirrors, light switches, wall and floor tiles, lighting, letter boxes, Roof tiles, gutters, antennas, satellite dishes, handrails of railings and escalators, architectural glazing, solar panels, conservatories, walls of elevators; Monuments, sculptures and generally works of art made of natural stone (e.g. granite, marble), metal etc., in particular also those that are set up outdoors. Means of transportation and transportation (e.g. cars, trucks, buses, motorbikes, mopeds, bicycles, trains, trams, ships and planes) and parts thereof:

0055Headlights, interior and exterior mirrors, windshields, rear windows, side windows, mudguards for bicycles and motorcycles, plastic visors for motorcycles, instruments for motorcycles, seats, saddles, door handles, steering wheels, tire rims, tank sockets (especially for diesel), license plates, luggage racks, roof containers for Cars and cockpits.

0056Work equipment, devices and machines for commercial or industrial purposes and research as well as parts thereof:

0057Molds (e.g. casting molds, especially made of metal), hoppers, filling systems, extruders, water wheels, rollers, conveyor belts, printing machines, screen printing stencils, filling machines, (machine) housings, injection molded parts, drilling heads, turbines, pipes (inside and outside), pumps, saw blades , Covers (e.g. for scales), keyboards, switches, buttons, ball bearings, shafts, screws, displays, solar cells, solar systems, tools, tool handles, liquid containers, isolators, capillaries, lenses, laboratory equipment (e.g. chromatography columns and fume cupboards) and computers (especially housings and monitor disks).

0058Household items and work equipment for the household or parts thereof:

0059Furniture veneers, furniture moldings, trash cans, toilet brushes, tablecloths, dishes (e.g. made of porcelain and earthenware), glassware, cutlery (e.g. knives), trays, pans, pots, baking tins, cooking utensils (e.g. Wooden spoons, rasps, garlic presses, etc.), hobs, heating plates, ovens (inside and outside), flower vases, covers for wall clocks, TV sets (especially screens), stereo systems, housings for (electrical) household appliances, picture glazing, Christmas baubles, wallpapers, lamps and lights, upholstered furniture, leather items. Equipment, devices and aids for games, sports and leisure:

0060Garden furniture, garden tools, greenhouses (especially glazing), tools, playground equipment (e.g. slides), balls, air mattresses, tennis rackets, table tennis rackets, table tennis tables, skis, snowboards, surfboards, golf clubs, dumbbells, seating in parks, playgrounds etc., motorcycle clothing, motorcycle helmets , Ski suits, ski boots, ski goggles, helmets for skiers, diving clothing and goggles.

0061Devices, aids and devices for medical purposes and the sick:

0062Prostheses (especially for limbs), implants, catheters, artificial intestinal exits, braces, dentures, glasses (glasses and frames), medical cutlery (for surgeries and dental treatments), plaster casts, clinical thermometers and wheelchairs and, in general, hospital facilities.

0063In addition to the above objects, other objects and parts thereof can of course also be advantageously coated with the above coating compositions, such as jewelry, coins, works of art (e.g. paintings), book covers, tombstones, urns, signs (e.g. traffic signs), neon signs, traffic lights, CDs, Bad weather clothing, textiles, post boxes, telephone booths, waiting booths for public transport, safety glasses, protective helmets, foils (e.g. for the packaging of food), telephones, seals for taps, generally all objects made of rubber, bottles, light, heat or pressure sensitive recording materials (before or after the recording, e.g. photos) and church windows.

0064With regard to the interference layers mentioned above, exemplary applications are mentioned:

0065Optical filters: anti-reflective and reflex filters in the field of the glasses industry, displays, screens, semiconductor lasers, microlens coatings, solar cells, "Damage-Resistanf 'laser layers. Holographic layers: light guiding systems, information storage, laser couplers, waveguides, decoration and architecture.

0066Embossable layers: anti-reflective systems, focusing in detector fields, lighting of flat screens, imaging in photocopiers, fiber optics (light coupling).

0067Lithography: Manufacture of micro-optical elements such as waveguides, gratings, pinholes, diffraction gratings (point gratings) as well as in the field of display technology, fiber chip coupling and imaging optics.

0068Burnable layers: color filters on metals, interference filters on glass such as bandpass filters, anti-reflection filters, absorption filters and beam splitters.

0069The following examples serve to further illustrate the present invention.

0070Example 1: Production of a transparent organic-free SiO₂Molded body

0071Si0₂Particles (OX-50, primary particle size 40 nm) are dispersed in a concentration of 10% by weight with stirring and ultrasound in isopropanol for about 30 minutes. Then 3-methacryloxypropyltrimethoxysilane (MPTS) in an amount of 6 wt .-%, based on the Si0₂Content, slowly added with stirring. The Si0 is silanized by stirring for 3 hours at 50.degree₂-Particles reached. 6% by weight (based on the total solids content) of tetraethylene glycol dimethacrylate (TEGDMA) are then added and the mixture is stirred for a further 15 minutes. Finally, 2 mol% of Irgacure are used as photo starters for UV polymerization^® 184 (Ciba-Geigy) added per mole of double bond. The solvent is then partially distilled off under vacuum (complete distillation of the alcohol leads to gel formation, so that a free-flowing or pourable suspension can no longer be obtained). The suspension thus obtained can be used directly for the production of bulk materials by photopolymerization. For this the Si0₂/ MPTS TEGDMA system cast in a polyethylene mold. For degassing, the viscous sol is again treated under vacuum (100 mbar) at 25 ° C. for 1 hour. A UV / IR combination dryer (Beltron company) is used to crosslink the organic portion. The power of the mercury vapor lamps is 400 mW / m each². The complete photopolymerization of a bulk of 5 mm thickness is achieved by an irradiation amount of 240 J / cm² reached. After the photopolymerization, a dimensionally stable body is obtained. By oven treatment at 80 ° C, crack-free drying of the photopolymerized bulk is carried out within one hour. This results in a solvent-free and binder-containing Si0₂-Shaped body that corresponds to a ceramic green body. In order to burn out the remaining organic fraction, the temperature of the furnace is increased from 80 ° C to 500 ° C within 3 hours, after which the latter temperature is maintained for a further 3 hours. So you get a porous Si0₂-Bulk, which, as can be deduced from IR spectroscopic investigations, is free of organic groups. Finally, the temperature is increased from 500 ° C to 1400 ° C within 3 hours and the latter temperature is then held for 2 hours. This finally gives a transparent molded body.

0072Example 2: Production of an organic-free transparent Zr0₂Molded body

0073Nanoscale zirconium oxide particles ("TOSOH-Zirconia TZ-8Y" with a primary particle size of 90 nm) are dispersed in isopropanol with stirring and ultrasound. For surface modification, 3.2% by weight (based on the Zr0₂Content) MPTS added with stirring. After stirring for 3 hours at 50 ° C., the Zr0 is silanized₂-Particles reached. 3.2% by weight (based on the Zr0₂Content) TEGDMA added and the mixture is stirred at 20 ° C. for a further 15 minutes. Then 3 mol% of Irgacure are used as the photo starter^® 184 per mole of double bond added. This is followed by partial removal of the solvent under vacuum. The resulting, still flowable suspension is used directly for the production of bulk materials by photopolymerization. In order to obtain a shaped body with a thickness of 5 mm, an output of 350 J / cm² used. By oven treatment of the photopolymerized molded body at 80 ° C., crack-free drying of the photopolymerized bulk is achieved within 30 minutes. This results in a solvent-free and binder-containing Zr0₂- Bulk, which corresponds to a ceramic green body. In order to burn out the remaining carbon, the temperature of the furnace is increased from 80 ° C to 450 ° C within 3 hours and kept at the latter temperature for 3 hours. A porous Zr0 is thus obtained₂-Bulk that is free of organic groups. Finally, the temperature is increased from 450 ° C to 1400 ° C within 3 hours and held at the latter value for 4 hours. The resulting sintered molded body is translucent to opaque.

0074Example 3: Synthesis of a sol to produce layers with a high refractive index

007586.861 g Ti0₂-Sol (3.5 wt% Ti0₂ in isopropanol; Particle size: 5 nm) are mixed with 1.989 g of tributyl phosphoric acid and stirred for 1 hour. The sol is then added dropwise at 100 ° C. with a solution of 1.2 g of distilled γ-glycidyloxypropyltrimethoxysilane (GPTS) in 100 g of 2-isopropoxyethanol. After stirring for 1 hour, the mixture is cooled to room temperature and 0.8775 g of hydrolyzed GPTS (prepared by adding 23.63 g of distilled GPTS with 2.70 g of 0.1 N HCl and stirring for 24 hours and then distilling off low molecular reaction products at 3 mbar) added. After stirring for 15 minutes, the mixture is distilled under vacuum (3 mbar) and then diluted with 120 g of 2-isopropoxyethanol. In this way a transparent, agglomerate-free sol is obtained.

0076Example 4: Synthesis of a sol to produce layers with a low refractive index

0077A mixture of 23.63 g GPTS (distilled) and 12.45 g tetraethoxysilane (TEOS) is mixed with 2.88 g 0.1 N HCl for hydrolysis and condensation. The resulting reaction mixture is then stirred for 24 hours at 20 ° C. and then subjected to vacuum distillation (at 3 mbar) in order to remove low molecular weight constituents. Finally, the remaining reaction product is diluted with 50 g of isopropoxyethanol as a solvent.

0078Example 5: Synthesis of a sol for the production of layers with a low refractive index and an additional easy-to-clean function

007926.63 g of distilled GPTS are mixed with 8.30 g of TEOS and 0.11 g of 1 H, 1 H, 2H, 2H-perfluorooctyltriethoxysilane (FTS) for 15 minutes with stirring. The resulting sol is hydrolyzed and condensed with 4.5 g of 0.1 N HCl at 20 ° C. for 4 hours with stirring. 52.10 g of isopropoxyethanol and 0.53 g of phosphoric acid are then added and the mixture is stirred at 20 ° C. for a further 2 hours.

0080Example 6: Production of a layer with the sol from Example 3 on glass

0081The sol from Example 3 is mixed with 0.08 g of Cyracure^® UVI-6974 (Ciba-Geigy) and 0.02 g of 1-methylimidazole were added. After intensive stirring, the mixture is filtered and can then be used as a coating varnish. Glass panes (10 cm x 10 cm x 2 mm) are cleaned with 2-propanol and dried in air before coating.

0082The coating varnish is applied to the substrate in a defined manner by spin coating. The layer thickness is controlled via the speed of rotation of the substrate.

0083A UV / IR combination dryer (from Beltron) is used to harden the layer. The device used has two mercury vapor lamps for irradiation with UV light, an IR radiator, the output of which can be used to regulate the surface temperature, and a treadmill on which the substrates can be guided under the UV / IR radiator at a defined speed. The power of the mercury vapor lamps is 400 mW / cm each². The IR emitter is set to 120 ° C, the belt speed is 2.6 m / min. and the coated substrates are passed a total of three times at these settings.

0084The last stage of curing consists of a 15-minute thermal post-treatment at 120 ° C in a circulating air dryer.

0085Example 7: Production of a Layer with the Sol from Example 3 on Polycarbonate (PC)

0086Polycarbonate panes (10 cm × 10 cm × 2 mm; pretreatment as in Example 6) are coated and cured with the coating material from Example 3 using the method of Example 6. Differences: the IR emitter is set to 100 ° C and the last stage of curing consists of a 30-minute thermal aftertreatment at 100 ° C in a circulating air dryer.

0087Example 8: Production of a layer with the sol from example 3 on polymethyl methacrylate (PMMA)

0088With the coating material from Example 3, polymethyl methacrylate disks (10 cm × 10 cm × 2 mm; pretreatment as in Example 6) are coated and cured according to the method of Example 6. Differences: no IR radiation and the last stage of curing consists of a 60-minute thermal aftertreatment at 80 ° C in a circulating air dryer.

0089Example 9: Production of a layer with the sol from example 4 on a PC

0090The coating material from Example 4 is coated with 0.72 g of Cyracure^® UVI-6974, 0.36 g of 1-methylimidazole and 10 g of a 0.02 percent by weight aluminum tributoxyethanolate solution in 2-isopropoxyethanol are added and mixed intensively. The necessary dilution is achieved by adding 50 g of 2-isopropoxyethanol. This coating material is used to coat and cure polycarbonate panes (see Example 7) using the method of Example 7. Differences: the substrates are four times at a belt speed of 2 m / min. Drive past and the last stage of curing consists of a 60-minute thermal aftertreatment at 100 ° C in a circulating air drying cabinet.

0091Example 10: Production of a layer with the sol from example 4 on PMMA

0092The procedure is as in Example 9, but without using the IR radiator. The last stage of curing consists of a 60-minute thermal aftertreatment at 70 ° C in a circulating air dryer.

0093Example 11: Production of a layer with the sol from example 5 on a PC

0094The coating material according to example 5 is provided with initiators according to example 8 and cured according to the method described in example 8.

0095Properties of the layers produced in Examples 6 to 11

0096Refractive index: ellipsometric

0097Transmission (550 nm): Spectroscopic (one-sided coating of the

0098Substrate) Reflection (550 nm): Spectroscopic (uncoated back of the

0099Blackened substrates) Adhesion (layer on substrate): Cross cut and tape test according to DIN 53151 and DIN 58196

0100The values ​​thus obtained are summarized in the following table.

0101<img file="WO9851747A1_D0001.tif" />Example 12: Coating of plastic substrates

0102248.8 g (1 mol) of MPTS are introduced and 136.84 g (43% by weight, based on the total solids content) of AIOOH nanopowder (Sol P3, 15 nm, Degussa) are added with stirring. The hydrolysis is carried out by slowly adding 36 g (2 mol) of deionized water and boiling at 100 ° C. for 2.5 hours. After cooling, the pre-hydrolyzate is diluted to a solids content of 45% with 282 g of 1-butanol and 3.5 g (0.5% by weight) of byc^®-306 added as leveling agent. For UV polymerization, 5.46 g (3 mol% based on the double bonds present) of benzophenone are added as a photo starter. The coating system is applied to various plastics by means of spin coating. The layer is cured by UV radiation using a mercury lamp for 2 minutes.

0103The coating shows good adhesion (GT / TT = 0/0) without substrate pretreatment, for example on PMMA. The scratch-resistant coating has an abrasion hardness of 11% after 1000 cycles (Taber Abraser, CS-10F, 500 g / roll).

0104Example 13: Coating of plastic substrates

0105The procedure of Example 12 is repeated, except that in addition to benzophenone, 1.05 g (1 mol%) of diethanolamine is used as an accelerator.

0106The coating shows good adhesion (GT TT = 0/0) without substrate pretreatment, for example on PMMA. The scratch-resistant coating has an abrasion hardness of 9% after 1000 cycles (Taber Abraser, CS-10F, 500 g / roll).

0107Example 14: Coating of plastic substrates

0108248.8 g (1 mol) of MPTS are introduced and 99.52 g (31% by weight, based on the total solids content) of AIOOH nanopowder (Sol P3, 15 nm, Degussa) are added with stirring. The hydrolysis is carried out by slowly adding 36 g (2 mol) of deionized water and boiling at 100 ° C. for 2.5 hours. After cooling, the pre-hydrolyzate with 49.5 g (15 mol%) TEGDMA and 3.9 g (0.5 wt .-%) Byk^®-306 added as leveling agent and diluted with 343 g of 1-butanol to a solids content of 45%. For UV polymerization, 0.6 g (2.5 mol% based on the double bonds present) of benzophenone are added as a photo starter. The coating system is applied to various plastics by means of spin coating. The layer is cured by UV radiation for 2 minutes using a mercury lamp.

0109The coating shows good adhesion (GT / TT = 0/0) without substrate pretreatment, for example on PMMA. The scratch-resistant coating has an abrasion hardness of 15% after 1000 cycles (Taber Abraser, CS-10F, 500 g / roll). Dimethacrylate increases the flexibility and water stability of the coating. (Storage at 65 ° C in deionized water> 14 days, without dimethacrylate 7 days.)