Nanostructured moulded bodies and layers and method for producing same

0001The present invention relates to nanostructured layers and to processes for their production. More particularly, the present invention relates to nanostructured layers produced by a wet chemical process.

0002Nanostructured materials have been known for a long time. They are generally produced by densifying nanoscale particles with diameters in the lower nanometer range by a suitable method (see, for example, US Pat<nplcit id="ncit0001" npl-type="b"><text>H. Gleiter, Nanocrystalline Materials, Pergamon Press, Oxford, 1989</text></nplcit>). This is usually done under high pressure. In this case, the high diffusion rates are exploited in the outer regions of the nanoscale particles, with compression (and, under certain circumstances, simultaneous exposure to elevated temperatures), densification to form dense bodies. Corresponding wet-chemical processes, such as the sol-gel process, generally lead to porous gels, since the binding of the particles takes place by the high surface activity of the particles, but the dense stringing together of the particles and the filling of the gusset does not take place. Materials produced by such processes are uniform, ie, they have interfacial phases whose composition is not (substantially) different from that of the particle phase (only the gas phase of the environment can be present in addition).

0003<patcit id="pcit0001" dnum="DE4336694A"><text>DE-A 43 36 694</text></patcit> Describes a process for producing ceramic or metal sintered bodies or layers by surface-modifying a nanocrystalline ceramic or metal powder specified in grain size in the presence of a low-molecular compound having a functional group in a dispersion, removing the dispersing medium, and subjecting the obtained surface-modified ceramic- Or metal powder.

0004<patcit id="pcit0002" dnum="DE19630100"><text>DE 196 30 100</text></patcit> Describes a process for the production of shaped bodies. Out<patcit id="pcit0003" dnum="DE19540623"><text>DE 195 40 623</text></patcit> There is known a process for the production of composite materials in which the filler particles are present in an agglomerate-free manner in a matrix phase. <patcit id="pcit0004" dnum="US4027073A"><text>US 4,027,073</text></patcit> Describes coating compositions of colloidal silica and partial condensates of a silanol which are thermally cured.

0005Surprisingly, it has now 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 which are comparable to those previously produced in a dry manner are accessible by a wet chemical method Or even superior. In particular, highlytransparent materials are also accessible in this way since the correlation lengths for the Raleigh scattering are not achieved by the small distances between the particles (one to a few nm).

0006The present invention accordingly provides a process for the production of nanostructured shaped bodies and layers which comprises the following steps:<ol><li>A) providing a nanoscale inorganic solid particle having polymerizable and / or polycondensable organic surface groups containing free-flowing mass;</li><li>B) applying the mass of step a) to a substrate;</li><li>C) polymerization and / or polycondensation of the organic surface groups of the inorganic solid particles to form a cured shaped body or a cured layer,</li></ol>Wherein step c) includes photochemical polymerization / polycondensation. In many cases, it may be advantageous if a thermal aftertreatment, preferably at a temperature in the range from 60 to 150 ° C., in particular from 80 to 130 ° C., of the hardened molded body or the hardened layer, follows the above step c) .

0007Alternatively or additionally, a (further) thermal densification of the layer can be carried out 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).

0008In some cases, it may also be advisable to carry out (further) thermal compaction at temperatures in the range from 800 to 1500 ° C., preferably from 1000 to 1400 ° C.

0009In general, a (post) treatment at temperatures of at least 350 ° C. makes it possible to use the nanoscale inorganic solid particles as a mechanically solid precursor for the production of a purely inorganic solid.

0010In the present description and the appended claims, "nanoscale inorganic solid particles" are intended to mean those having an average particle size (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 from 5 to 50 nm.

0011The nanoscale inorganic solid particles can consist of any materials, but are preferably made of metals and, in particular, of metal compounds such as, for example, (hydrated) oxides, such as ZnO, CdO, SiO₂, TiO₂, ZrO₂, CeO₂, SnO₂, Al₂O₃, In₂O₃, La₂O₃, Fe₂O₃, Cu₂O, Ta₂O₅, Nb₂O₅, V₂O₅, MoO₃ or where₃; Chalcogenides, for example sulfides (eg CdS, ZnS, PbS and Ag₂S), selenides (eg GaSe, CdSe and ZnSe) and tellurides (eg ZnTe or CdTe), halides such as AgCl, AgBr, Agl, CuCl, 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, AlN, Si₃N₄ And Ti₃N₄; Phosphides such as GaP, InP, Zn₃P₂ And Cd₃P₂; Phosphates, silicates, zirconates, aluminates, stannates and the corresponding mixed oxides (eg those with a perovskite structure such as BaTiO₃ And PbTiO₃).

0012The nanoscale inorganic solid particles used in step a) of the process according to the invention are preferably those of oxides, sulfides, selenides and tellurides of metals and mixtures thereof. According to the invention, particular preference is given to nanoscale particles of SiO₂, TiO₂, ZrO₂, ZnO, Ta₂O₅, SnO₂ And Al₂O₃ (In all modifications, especially as boehmite, AlO (OH)) and mixtures thereof.

0013Since the nanoscale particles which can be used according to the invention cover a wide range of refractive indices, the refractive index can be determined by suitable selection of these nanoscale particles. Of a layer can conveniently be adjusted to the desired value.

0014The nanoscale solid particles used according to the invention can be produced in a conventional 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 methods and (micro) These methods are described in detail in the literature. In particular, for example, metals (for example after the reduction of the precipitation processes), ceramic oxidic systems (by precipitation from solution), but also salt-like or multicomponent systems can be used. The salt-like or multi-component systems also include semiconductor systems.

0015The nanoscale inorganic solid particles which are provided with polymerizable and / or polycondensable organic surface groups and 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 secondly by the preparation of these inorganic nanoscale solid particles Using one or more compounds which have such polymerizable and / or polycondensable groups. These two routes are explained in more detail below and in the examples.

0016The organic polymerizable and / or polycondensable surface groups can be any groups known to a person skilled in the art which are capable of free-radical, cationic or anionic, thermal or photochemical polymerization or a thermal or photochemical polycondensation (if appropriate in the presence of a suitable initiator or catalyst) Are accessible. According to the invention, preference is given to surface groups which have a (meth) acrylic, allyl, vinyl or epoxy group, with (meth) acrylic and epoxy groups being particularly preferred. Among the polycondensable groups, hydroxy, carboxy and amino groups may be mentioned, by means of which ether, ester and amide bonds can be obtained between the nanoscale particles.

0017According to the invention it is also preferred 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. This, of course, does not exclude a significantly higher molecular weight of the compounds (molecules) comprising these groups (eg, 1000 and more).

0018As already mentioned above, the polymerizable / polycondensable surface groups can in principle be provided in two ways. If a surface modification of already produced nanoscale particles is carried out, all (preferably low molecular weight) compounds which, on the one hand, have one or more groups which are present on (functional) groups (such as, for example, OH groups) present on the surface of the nanoscale solid particles, are suitable for this purpose In the case of oxides), or at least one polymerizable / polycondensable group. Thus, the corresponding compounds can form, for example, both covalent and ionic (salt-like) or coordinative (complex) bonds to the surface of the nanoscale solid particles, while, among the pure interactions, dipole-dipole interactions, hydrogen bonds and van der Waals interactions . Preference is given to the formation of covalent and / or coordinative bonds. Concrete examples of organic compounds which can be used for the surface modification of the nanoscale inorganic solid particles are, for example, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, β-dicarbonyl compounds (eg β-diketones or β-carbonylcarboxylic acids) with polymerizable double bonds, ethylenically unsaturated alcohols and amines, epoxides and the like. According to the invention, particularly suitable as such compounds are hydrolytically condensable silanes with at least (and preferably) a non-hydrolysable radical which has a polymerizable carbon-carbon double bond or an epoxide ring, in particular in the case of oxidic particles. Such silanes preferably have the general formula (I):         XR¹-SiR²₃     (I) Wherein X is CH₂= CR³-COO, CH₂= CH or glycidyloxy, R³ Hydrogen or methyl, R¹ Is a divalent hydrocarbon radical having 1 to 10, preferably 1 to 6, carbon atoms, optionally containing one or more heteroatom moieties (eg, O, S, NH) separating 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).

0019Preferably, the groups are R;² Identical and selected from halogen atoms,_1-4Alkoxy groups (eg methoxy, ethoxy, n-propoxy, i-propoxy and butoxy), C_6-10Aryloxy groups (eg, phenoxy), C_1-4Acyloxy groups (eg acetoxy and propionyloxy) and C_2-10Alkylcarbonyl groups (eg, acetyl).

0020Particularly preferred radicals R² Are C_1-4And especially methoxy and ethoxy.

0021For the rest R¹ Is preferably an alkylene group, in particular one having 1 to 6 carbon atoms, for example ethylene, propylene, butylene and hexylene. If X is CH₂= CH, R represents¹ Preferably methylene, and in this case can also mean a mere bond.

0022Preferably X is CH₂= CR³-COO (wherein R³ Preferably CH₃ (Meth) acryloyloxyalkyltrialkoxysilanes such as, for example, 3-methacryloyloxypropyltri (m) ethoxysilane and glycidyloxyalkyltrialkoxysilanes, for example 3-glycidyloxypropyltri (m) ethoxysilane, are particularly preferred.

0023If the nanoscale inorganic solid particles are prepared using one or more compounds which have polymerizable / polycondensable groups, subsequent surface modification can be omitted (although this is, of course, possible as an additional measure).

0024The in situ preparation of nanoscale inorganic solid particles with polymerizable / polycondensable surface groups is described in the following by the example of SiO₂Particles. For this purpose,₂Particles can be prepared, 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) described above. These silanes are preferably used either alone or in combination with a suitable silane of the general formula (II)         SiR²₄     (II) Wherein R² Is as defined above. Preferred silanes of the above general formula (II) are tetramethoxysilane and tetraethoxysilane.

0025It is, of course, also possible, in addition to or as an alternative to the silanes of the general formula (II), to use other silanes, for example those having a (nonhydrolyzable) hydrocarbon group without any functional group, such as, for example, methyl or phenyltrialkoxysilanes. Particularly when an easy to clean surface of the shaped body or the layer is desired, it may be advisable to use, in addition to the silanes of the general formula (I) and, if appropriate, the general formula (II), a certain amount (for example bis To 60 and, in particular, up to 50 mole percent based on all silanes used), silanes with fluorine-containing (non-hydrolysable) radicals, in particular hydrocarbon radicals. Particular preference is given here to silanes of the above formula (I), in which R 1² As defined above, R is¹ Represents an ethylene group and X represents a perfluoroalkyl group having 2 to 12, preferably 4 to 8, carbon atoms. Further silanes which can be used for this purpose are, for example, those having (per) fluorinated aryl (especially phenyl) groups. Of course, such fluorinated silanes can also be used for the surface modification of already finished nanoscale inorganic solid particles.

0026The material used in stage a) of the process according to the invention is in the form of a still flowable mass (suspension). The liquid constituent of this composition is composed, for example, of water and / or (preferably water-miscible) organic solvents and / or compounds which have been used or produced during the preparation of the nanoscale particles or their surface modification (eg alcohols in the case of alkoxysilanes) , together. Examples of suitable suitable organic solvents are, for example, alcohols, ethers, ketones, esters, amides and the like. An (additional) component of the flowable mass can, for example, also be at least one monomeric or oligomeric species which has at least one group which can polymerize (polymerize or polycondensate) with the polymerizable / polycondensable groups present on the surface of the nanoscale particles. Examples of such species are, for example, monomers having a polymerizable double bond, for example acrylic acid ester, methacrylic acid ester, styrene, vinyl acetate and vinyl chloride. As (preferably used) monomeric compounds having more than one polymerizable bond, particular mention may be made of those of the general formula (III):         (CH₂= CR³-COZ-)_N-A (III) wherein<ul><li>N = 2, 3 or 4, preferably 2 or 3 and in particular 2;</li><li>Z is O or NH, preferably O;</li><li>R³= H, CH₃;</li><li>A = n-valent hydrocarbon radical having 2 to 30, in particular 2 to 20, carbon atoms, which can have one or more heteroatom groups which are in each case between two adjacent carbon atoms (examples of such heteroatom groups being O, S, NH, NR (R = ), Preferably O).</li></ul>

0027Furthermore, 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 -C 6)_1-4Alkoxy), hydroxy, optionally substituted amino, NO₂, OCOR⁵, COR⁵ (R.⁵ = C_1-6Alkyl or phenyl). However, the radical A is preferably unsubstituted or substituted by halogen and / or by hydroxy.

0028In a particularly preferred embodiment of the present invention, A is derived from an aliphatic diol, an alkylene glycol, a polyalkylene glycol or a optionally alkoxylated (eg ethoxylated) bisphenol (eg bisphenol A)

0029Further usable compounds having 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 of the use of epoxy-containing surface groups), for example bisphenol A diglycidyl ether or also an (oligomeric) precondensate of an epoxide group-containing hydrolyzable silane (eg glycidoxypropyltrimethoxysilane).

0030When additional monomeric compounds having 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) out.

0031In step b) of the process according to the invention, the flowable mass of stage a) is applied to a desired substrate in order to coat the substrate completely or partially. The coating methods suitable for this purpose are the conventional ones known to those skilled in the art. Examples of this are dipping, spraying, knife coating, brushing, brushing, centrifuging, etc.

0032Before being applied to the substrate, the flowable mass can be adjusted to a suitable viscosity, for example, by the addition of solvent or evaporation of volatile constituents (in particular already present solvent).

0033For the coating with the flowable mass of step a) of the process according to the invention, substrates of any materials, in particular of plastics, metal and glass, are suitable. These substrate materials may be subjected to a surface treatment (eg degreasing, roughening, corona discharge, treatment with a primer, etc.) before the application of the flowable mass. Particularly in the case of coating of plastic substrates, a suitable adhesion can be provided by the addition of a suitable monomeric polymerizable compound and / or according to the preferred embodiment described in more detail below.

0034Among the metal substrates which can be coated according to the invention are, for example, metals such as, for example, aluminum, copper, zinc, nickel and chromium and metal alloys such as (noble) steel, brass and bronze. Suitable plastic substrates are, for example, those of polycarbonate, polyesters, polyamides, polystyrene, poly (meth) acrylates (eg polymethylmethacrylate), PVC, polyolefins (such as polyethylene and polypropylene), and rubbers (ABS, NBS, etc.) and polyphenylenesulfide call.

0035In step c) of the process according to the invention, a polymerisation 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 the expert. Examples of suitable processes are thermal, photochemical (eg with UV radiation), electron beam curing, laser hardening, room temperature curing, etc. If desired, such a polymerization / polycondensation is carried out in the presence of a suitable catalyst or initiator which corresponds to the flowable mass of step A) is added to the substrate at the latest immediately before it is introduced into the mold or application.

0036Suitable starter / starter systems are all known starter / starter systems known to a person skilled in the art, including free-radical photostarter, free-radical thermostarter, cationic photostarter, cationic thermostarter and any combinations thereof.

0037Concrete examples of free-radical photostats which can be used are Irgacure^® 184 (1-hydroxycyclohexyl phenyl ketone), Irgacure^® 500 (1-hydroxycyclohexyl phenyl ketone, benzophenone) and other photoinitiators available from Ciba-Geigy from Irgacure^®-Type; Darocur^® 1173, 1116, 1398, 1174 and 1020 (available from Merck); Benzophenone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, benzoin, 4,4'-dimethoxybenzoin, benzoinethylether, benzoinisopropylether, benzil dimethyl ketal, 1,1,1-trichloroacetophenone, diethoxyacetophenone and dibenzosuberone.

0038Examples of radical thermostarter include organic peroxides in the form of diacyl peroxides, peroxydicarbonates, alkyl peresters, alkyl peroxides, perketals, ketone peroxides and alkyl hydroperoxides, as well as azo compounds. Specific examples which may be mentioned here are, in particular, dibenzoyl peroxide, tert-butyl perbenzoate and azobisisobutyronitrile.

0039An example of a cationic photostarter is Cyracure^® UVI-6974, while a preferred cationic thermostarter is 1-methylimidazole.

0040These initiators are used in the customary amounts known to a person skilled in the art (preferably from 0.01 to 5% by weight, in particular from 0.1 to 2% by weight, based on the total solids content of the flowable mass of stage a). Obviously, the starter can be dispensed with under certain circumstances, such as, for example, in the case of electron beam or laser curing.

0041The polymerization / polycondensation of stage c) of the process according to the invention is preferably carried out by irradiation (in particular with UV light). Particular preference is given to a photochemical polymerization / polycondensation or a combination of thermal and photochemical polymerization / polycondensation.

0042The polymerization / polycondensation can proceed to removal of further volatile, non-polymerizable / non-polycondensable compounds on the substrate. This removal of volatile constituents can, however, also be carried out additionally or at the stage of the polymerization / polycondensation or thereafter.

0043In the following, a typical method according to the invention, which can lead to layers, is given by way of example, the stated ranges of values ​​and procedures being generally valid irrespective of the materials used.

0044For layer formation, it is possible, for example, to carry out 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, of sols with, for example, Or sulfide nanoparticles. After viscosity adjustment by addition or removal of solvent (eg alcohol) and after addition of a photoinitiator (eg at a concentration of 5% by weight, based on the silane used), curing of the layer on the selected substrate preferably leads to UV light 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 indispensable. The layers thus produced 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 the silane used and the addition of an additional organic monomer (methacrylates, acrylates, etc.), the possibility of the adhesion properties of the layer is obtained in low concentrations (for example &lt;5% by weight) To adapt the substrate so that, for example, glass and plastics can be coated equally. Furthermore, the use of the abovementioned 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.

0045Particularly for the coating of plastic substrates, according to a preferred embodiment of the present invention, nanoparticles (in particular those of AlOOH, ZrO₂, TiO₂ And the like) in relatively high concentrations (as a rule at least 15% by weight 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% In particular, 25% by volume) is dispersed in a liquid system comprising, as an essential constituent, at least one hydrolyzable silane with a polymerizable / polycondensable group (for example, one of the above general formula (I)), followed by a (conventional) ) Prehydrolysis of the silane. In addition to the silane with a polymerizable / polycondensable group, other hydrolyzable components, in particular other (optionally fluorinated) silanes (for example those of the above general formula (II)) and / or hydrolyzable compounds (eg alkoxides, halides) of main and secondary groups, may also be present (Eg, Al, Ti, Zr). After the pre-hydrolysis, further species having more than one (preferably two) copolymerizable / copolycondensible groups (especially those of the above general formula (III), preferably in amounts of up to 40, in particular up to 30 and particularly preferably up to 15 wt. %) Are added. As the polymerizable groups, (meth) acrylate groups are particularly preferred. Before application to a plastic substrate, a solvent (eg an alcohol) can also be added to this system for viscosity adjustment, as are customary lacquer additives (see below). Although the resulting varnish can be thermally cured (preferably after the addition of a corresponding thermostat), it has surprisingly been found that a photoinitiator (preferably in the abovementioned customary amounts) also uses photochemical curing (preferably with UV light) (Eg, in the case of polycarbonates, polystyrene, poly (meth) acrylate, etc.), a highly scratch-resistant, transparent layer which also adheres well to most plastic substrates without pretreatment of the surfaces thereof.

0046It is of course also possible to add dyes, pigments, matting agents etc. to the corresponding coating composition if a colored or non-transparent layer is desired. Examples of further customary additives for compositions of the type described are flow additives, UV absorbers, antioxidants (eg HALS), antistatic agents, surfactants (for hydrophilic surfaces) and fluorinated compounds (for hydrophobic / oleophobic surfaces).

0047An additional advantage of the above-described procedure is that, since solvent is preferably added without separately added (except for the purpose of viscosity adjustment after the prehydrolysis), a solvent exchange often described in the prior art is not required prior to application.

0048In the case of the layers according to the invention, scratch-resistant coatings with functional properties (antireflex, corrosion protection, hydrophilicity, hydrophobicity, antistatic layers) would generally be mentioned. Coating materials include, but are not limited to, transparent and non-transparent plastics, glass, metals, stone, wood, paper and textiles.

0049In particular, the present coating compositions are suitable for the coating of structures and parts thereof; Moving and transporting means and parts thereof; Machinery and equipment for industrial or industrial purposes and research and parts thereof; Household articles and household appliances and parts thereof; Equipment, devices and aids for games, sports and leisure activities and parts thereof; As well as devices, aids and devices for medical purposes and the sick. These compositions are also very suitable for the preparation of interference layers. Concrete examples of coating materials are given below:<ul><li>Buildings (in particular buildings) and parts thereof:<ul><li>(Window frames, window sills, glass or plastic windows and window handles), Venetian blinds, roller blinds, blinds, roller shutters, Doors, door handles, fittings in kitchen, bathroom and WC, shower cubicles, sanitary units, toilet cabins, pipes, radiators, mirrors, light switches, wall and floor tiles, lighting, letterboxes, roof tiles, rain gutters, antennas, satellite dishes, handrails of railings and escalators , Architectural glazing, sun collectors, winter gardens, walls of elevators; Monuments, sculptures and generally sculptures made of natural stone (eg granite, marble), metal etc., in particular also those which are placed outdoors.</li></ul></li></ul>

0050(Eg passenger cars, lorries, buses, motorbikes, mopeds, bicycles, railways, trams, ships and aircraft) and parts thereof:<ul><li>(Especially for diesel), license plates, luggage carriers, roof boxes for cars, bicycles, motorcycles, bicycles, motorcycles, Cars as well as cockpits.</li></ul>

0051Machinery and equipment for industrial or industrial use and research and parts thereof:<ul><li>Molds (eg casting molds, in particular metal), bulkheads, filling machines, extruders, water wheels, rollers, conveyor belts, printing machines, screen printing scrapings, filling machines, machine housings, injection moldings, drill heads, turbines, internal and external pipes, pumps, saw blades , Caps, displays, solar cells, solar panels, tools, tool handles, liquid containers, isolators, capillaries, lenses, laboratory equipment (eg chromatography columns and prints) and computers (especially housings And monitor discs).</li></ul>

0052Household articles and household appliances and parts thereof:<ul><li>(For example knives), trays, pans, pots, baking trays, cooking utensils (eg cooking spoons, graters, garlic presses, etc.), cooking troughs , Interior furnishing, heating systems, ovens (interior and exterior), flower vases, covers of wall clocks, TV sets (in particular screens), stereo systems, housings of (electrical) domestic appliances, picture glazing, Christmas tree decorations, wallpapers, lamps and lamps.</li></ul>

0053Equipment, tools and aids for game, sport and leisure:<ul><li>Garden furniture, greenhouses (in particular glazing), tools, playground equipment (eg slides), balls, air mattresses, tennis rackets, table tennis racquets, table tennis tables, skis, snowboards, surfboards, golf clubs, dumbbells, playgrounds in parks, playgrounds, motorbike clothing, motorcycle helmets , Ski suits, ski boots, ski goggles, skis for skiers, diving clothes and diving bats.</li></ul>

0054Medical and surgical appliances and appliances:<ul><li>Prostheses (especially for limbs), implants, catheters, artificial intestines, braces, dentures, spectacles, medical instruments (for operations and dental treatments), gypsum dressings, fever thermometers and wheelchairs.</li></ul>

0055In addition to the above objects, of course, other objects and parts thereof can advantageously be coated with the above coating compositions, such as jewelery, coins, works of art (eg paintings), book covers, gravestones, urns, signs (eg traffic signs), illuminated signs, (Eg for the packing of foodstuffs), telephone sets, gaskets for water faucets, generally all articles made of rubber, bottles, light, heat Or print-sensitive recording materials (before or after recording, eg photos) and church windows.

0056Regarding the above-mentioned interference layers, exemplary applications are:<ul><li><u>Optical filters:</u> Antireflective and reflex filters in the field of spectacle industry, displays, screens, semiconductor lasers, microlens coatings, solar cells, "Damage-Resistant" laser layers.</li></ul>

0057<u>Holographic Layers:</u> Light control systems, information storage, laser couplers, waveguides, decoration and architecture.

0058<u>Embossable</u><u>Layers:</u> Antireflection systems, focussing in detector fields, illumination of flat screens, imaging in photocopiers, fiber optics (light coupling).

0059<u>Lithograph:</u> Production of micro-optic elements such as waveguides, gratings, pinholes, diffraction gratings (dot grids) as well as in the field of display technology, fiber chip coupling and imaging optics.

0060<u>Burnout layers:</u> Color filters on metals, interference filters on glass such as, for example, bandpass filters, antireflection filters, absorption filters and beam splitters.

0061The following examples serve to further illustrate the present invention.

Example 1: Synthesis of a sol for the production of high-refractive-index layers

006286.861 g of TiO₂-Sol (3.5 wt% TiO₂ In isopropanol; Particle size: 5 nm) are admixed with 1.989 g of phosphoric acid tributyl ester 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 batch 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 0.1N HCl and stirring for 24 hours, followed by distilling off Low molecular weight reaction products at 3 mbar). After 15 minutes of stirring, the batch is distilled under vacuum (3 mbar) and then diluted with 120 g of 2-isopropoxyethanol. Thus, a transparent, agglomerate-free sol is obtained.

Example 2: Synthesis of a sol for the production of low-refractive-index layers

0063A mixture of 23.63 g of GPTS (distilled) and 12.45 g of tetraethoxysilane (TEOS) is treated with 2.88 g of 0.1 N HCl for hydrolysis and condensation. The resulting reaction mixture is subsequently stirred at 20 ° C. for 24 hours and then subjected to vacuum distillation (at 3 mbar) for the removal of low molecular weight components. Finally, the remaining reaction product is diluted with 50 g of isopropoxyethanol as solvent.

Example 3: Synthesis of a sol for the production of layers with a low refractive index and additional easy-to-clean function

006426.63 g of distilled GPTS are mixed with 8.30 g of TEOS and 0.11 g of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (FTS) for 15 minutes with stirring. The resulting sol is hydrolyzed and condensed with 4.5 g of 0.1N 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.

EXAMPLE 4 Preparation of a layer with the sol from Example 1 on glass

0065The sol from Example 1 is mixed with 0.08 g of Cyracure^® UVI-6974 (Ciba-Geigy) and 0.02 g of 1-methylimidazole. After intensive stirring, the mixture is filtered and can then be used as a coating lacquer. Glass panes (10 cm x 10 cm x 2 mm) are cleaned with 2-propanol and dried in air before coating.

0066The coating lacquer is applied to the substrate by spin coating. The layer thickness is controlled by the speed of rotation of the substrate.

0067A UV / IR combi-dryer (from Beltron) is used for the curing of the layer. The device used has two mercury vapor lamps for irradiation with UV light, an IR radiator, which can be used to control the surface temperature, and a treadmill on which the substrates can be passed at a defined speed under the UV / IR radiator. The performance of the mercury vapor lamps is 400 mW / cm².

0068The IR emitter is set to 120 ° C, the tape speed is 2.6 m / min. And the coated substrates will pass a total of three times in these settings.

0069The final stage of curing consists of a 15 minute thermal aftertreatment at 120 ° C in a circulating air drying cabinet.

EXAMPLE 5 Preparation of a layer using the sol from Example 1 on polycarbonate (PC)

0070Using the coating material from Example 1, polycarbonate wafers (10 cm × 10 cm × 2 mm, pretreatment as in Example 4) are coated and cured according to the procedure of Example 6. Differences: the IR radiator is set to 100 ° C. and the last stage of the curing consists of a 30-minute thermal aftertreatment at 100 ° C. in a circulating air drying cabinet.

EXAMPLE 6 Preparation of a layer using the sol from Example 1 on polymethyl methacrylate (PMMA)

0071Using the coating material from Example 1, polymethyl methacrylate wafers (10 cm × 10 cm × 2 mm, pretreatment as in Example 4) are coated and cured by the method of Example 4. Differences: no IR irradiation and the final stage of curing consists of a 60 minute thermal aftertreatment at 80 ° C in a circulating air drying cabinet.

Example 7: Preparation of a layer using the sol from Example 2 on PC

0072The coating material from Example 2 is mixed with 0.72 g of Cyracure^® UVI-6974, 0.36 g of 1-methylimidazole and 10 g of a 0.02% by weight aluminum tributoxyethanolate solution in 2-isopropoxyethanol and mixed intensively. The necessary dilution is achieved by the addition of 50 g of 2-isopropoxyethanol. Polycarbonate wafers (see Example 1) are coated with this coating material by the process of Example 5 and cured.

0073Differences: the substrates are washed four times at a belt speed of 2 m / min. And the final stage of curing consists of a 60 minute thermal aftertreatment at 100 ° C in a circulating air drying cabinet.

EXAMPLE 8 Preparation of a layer using the sol from Example 2 on PMMA

0074The procedure is as in Example 7, but without using the IR radiator. The final stage of curing consists of a 60-minute thermal aftertreatment at 70 ° C. in a circulating air drying cabinet.

EXAMPLE 9 Preparation of a layer using the sol from Example 3 on a PC

0075The coating material according to Example 3 is provided with initiators according to Example 6 and cured by the method described in Example 6.<tables id="tabl0001" num="0001"><table frame="none"><title><u>Properties of the compounds shown in Examples 4 to 6</u><u>9</u><b>Examination methods:</b></title><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="63mm" /><colspec colnum="2" colname="col2" colwidth="103mm" /><tbody><row><entry>Power Rating:</entry><entry>Ellipsometric</entry></row><row><entry>Transmission (550 nm):</entry><entry>Spectroscopic (one-sided coating of substrates)</entry></row><row><entry>Reflection (550 nm):</entry><entry>Spectroscopically (uncoated backside of substrates blackened)</entry></row><row><entry>Adhesion (layer on substrate):</entry><entry>Grid cut and adhesive tape test according to DIN 53151 and DIN 58196</entry></row></tbody></tgroup></table></tables>

0076The values ​​thus obtained are summarized in the following table.<tables id="tabl0002" num="0002"><table frame="all"><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="22mm" /><colspec colnum="2" colname="col2" colwidth="29mm" /><colspec colnum="3" colname="col3" colwidth="32mm" /><colspec colnum="4" colname="col4" colwidth="30mm" /><colspec colnum="5" colname="col5" colwidth="24mm" /><colspec colnum="6" colname="col6" colwidth="17mm" /><thead><row><entry valign="top">Example no.</entry><entry valign="top">Substrate material</entry><entry valign="top">Refractive index (550 nm)</entry><entry valign="top">Transmission [%]</entry><entry align="center" valign="top">Reflection [%]</entry><entry align="center" valign="top">liability</entry></row></thead><tbody><row><entry align="center">4</entry><entry align="center">Glass</entry><entry align="center">1.91</entry><entry align="center">78.5</entry><entry align="center">20</entry><entry align="center">0/0</entry></row><row><entry align="center">5</entry><entry align="center">PC</entry><entry align="center">1.91</entry><entry align="center">81</entry><entry align="center">19</entry><entry align="center">0/0</entry></row><row><entry align="center">6</entry><entry align="center">PMMA</entry><entry align="center">1.91</entry><entry align="center">78.5</entry><entry align="center">20</entry><entry align="center">0/0</entry></row><row><entry align="center">7</entry><entry align="center">PC</entry><entry align="center">1.47</entry><entry align="center">91</entry><entry align="center">8th</entry><entry align="center">0/0</entry></row><row><entry align="center">8th</entry><entry align="center">PMMA</entry><entry align="center">1.47</entry><entry align="center">91</entry><entry align="center">8th</entry><entry align="center">0/0</entry></row><row><entry align="center">9</entry><entry align="center">PC</entry><entry align="center">1.44</entry><entry align="center">95</entry><entry align="center">2.5</entry><entry align="center">0/0</entry></row></tbody></tgroup></table></tables>

EXAMPLE 10 Coating of plastic substrates

0077248.8 g (1 mol) of MPTS are introduced into the reaction vessel and mixed with 136.84 g (43% by weight, based on the total solids content) of AIOOH nanopowder (Sol P3, 15 nm, Degussa). The hydrolysis is carried out by the slow addition of 36 g (2 mol) of deionized water and 2.5 h of boiling at 100 ° C. After cooling, the prehydrolyzate is diluted with 282 g of 1-butanol to a solids content of 45% and admixed with 3.5 g (0.5% by weight) of by-products^®-306 as the flow agent. For the UV polymerization, 5.46 g (3 mol% based on the double bonds present) of benzophenone are added as photostarter. The application of the coating system to various plastics is carried out by centrifugal coating. The layer is cured by 2 minute UV irradiation using a mercury lamp.

0078The coating shows good adhesion (GT / TT = 0/0) without substrate pretreatment, eg on PMMA. The scratch-resistant coating has an abrasion hardness of 11% after 1000 cycles (Taber Abraser, CS-10F, 500 g / roll).

Example 11 Coating of Plastic Substrates

0079The procedure of Example 10 is repeated, except that 1.05 g (1 mol%) of diethanolamine is used as the accelerator in addition to benzophenone.

0080The coating shows good adhesion (GT / TT = 0/0) without substrate pretreatment, eg on PMMA. The scratch-resistant coating has an abrasion hardness of 9% after 1000 cycles (Taber Abraser, CS-10F, 500 g / roll).

Example 12 Coating of Plastic Substrates

0081248.8 g (1 mol) of MPTS are introduced into the reaction vessel and the mixture is admixed with 99.52 g (31% by weight, based on the total solids content) of AIOOH nanopowder (Sol P3, 15 nm, Degussa). The hydrolysis is carried out by slow addition of 36 g (2 mol) of deionized water and 2.5 h of boiling at 100 ° C. After cooling, the prehydrolyzate is reacted with 49.5 g (15 mol%) of TEGDMA and 3.9 g (0.5 wt.%) Of Byk^®-306 as a leveling agent and diluted with 343 g of 1-butanol to a solids content of 45%. For the UV polymerization, 0.6 g (2.5 mol% based on the double bonds present) of benzophenone are added as photostarter. The application of the coating system to various plastics is carried out by centrifugal coating. The layer is cured by 2 minute UV irradiation with a mercury lamp.

0082The coating shows good adhesion (GT / TT = 0/0) without substrate pretreatment, eg PMMA. The scratch-resistant coating has an abrasion hardness of 15% after 1000 cycles (Taber Abraser, CS-10F, 500 g / roll). The dimethacrylate increases the flexibility and the water stability of the coating. (Storage at 65 ° C in deionized water> 14 days, without dimethacrylate 7 days.)