Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/42—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating of an organic material and at least one non-metal coating
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C1/00—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels
  • C03C1/006—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels to produce glass through wet route
  • C03C1/008—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels to produce glass through wet route for the production of films or coatings
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/006—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character
  • C03C17/007—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/006—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character
  • C03C17/008—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character comprising a mixture of materials covered by two or more of the groups C03C17/02, C03C17/06, C03C17/22 and C03C17/28
  • C03C17/009—Mixtures of organic and inorganic materials, e.g. ormosils and ormocers
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/21—Oxides
  • C03C2217/213—SiO2
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/21—Oxides
  • C03C2217/214—Al2O3
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/21—Oxides
  • C03C2217/23—Mixtures
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/40—Coatings comprising at least one inhomogeneous layer
  • C03C2217/425—Coatings comprising at least one inhomogeneous layer consisting of a porous layer
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/40—Coatings comprising at least one inhomogeneous layer
  • C03C2217/43—Coatings comprising at least one inhomogeneous layer consisting of a dispersed phase in a continuous phase
  • C03C2217/46—Coatings comprising at least one inhomogeneous layer consisting of a dispersed phase in a continuous phase characterized by the dispersed phase
  • C03C2217/47—Coatings comprising at least one inhomogeneous layer consisting of a dispersed phase in a continuous phase characterized by the dispersed phase consisting of a specific material
  • C03C2217/475—Inorganic materials
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/70—Properties of coatings
  • C03C2217/73—Anti-reflective coatings with specific characteristics
  • C03C2217/732—Anti-reflective coatings with specific characteristics made of a single layer
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/70—Properties of coatings
  • C03C2217/76—Hydrophobic and oleophobic coatings
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2218/00—Methods for coating glass
  • C03C2218/10—Deposition methods
  • C03C2218/11—Deposition methods from solutions or suspensions
  • C03C2218/113—Deposition methods from solutions or suspensions by sol-gel processes

Definitions

• the invention generally relates to antireflection coatings and, preferably, to porous antireflection coatings and to processes for producing articles provided with such coatings.
• optical interference coating systems are known in which alternating high ⁇ two or more layers or low refractive index materials are superimposed.
• Wavelength range and for a defined range of angles of incidence of such layer systems the light waves reflected at the interface are at least partially canceled by destructive interference and thus the proportion of the reflected light is reduced.
• a broadband light source such as the Light of the sun, or a bigger one
• single layers can be used which show a good antireflection effect if their refractive index corresponds approximately to the root of the refractive index value of the underlying substrate.
• the methods for applying simple antireflection coatings described since then can be subdivided essentially into three groups.
• the first describes the etching of glass, the second a porous coating and the third a combination of the former two.
• porous layers produced by the etching of glass can only be produced with glasses that undergo phase separation, such as borosilicate glass of composition 55-82% SiO 2 , 12-30% B 2 O 3 , 2. 12%, alkali metal oxides and 0-7% Al 2 O 3 .
• glasses that undergo phase separation such as borosilicate glass of composition 55-82% SiO 2 , 12-30% B 2 O 3 , 2. 12%, alkali metal oxides and 0-7% Al 2 O 3 .
• disadvantageous are the expensive etching processes and the use of difficult-to-handle acids, such as, for example, NH 4 F-HF.
• porous antireflection coatings can store water during storage in air, in particular by absorbing atmospheric moisture, and may lose part of the antireflective effect.
• the minimum reflectivity for coatings on both sides can increase to values above approximately 4%.
• the favorable optical properties when used in photovoltaics or thermal solar collectors are thereby greatly impaired.
• DE 100 18 671 A1 discloses an article, in particular made of glass or a ceramic material, with a thin underlayer of a metal compound with preferably 4-valent metals such as Si, Ti, Zr, which are burned out at very high temperatures with decomposition of the organic fractions , After cooling, a hydrophobic organic layer is applied to this underlayer and dried.
• a metal compound with preferably 4-valent metals such as Si, Ti, Zr
• US 6066401 describes a process for the double coating of glass, in which on a substrate one of a metal fluoride, preferably MgF ⁇ and one of porous
• the object of the invention is to provide a process for producing an antireflection coating which preferably has increased chemical and mechanical resistance and is preferably resistant to water absorption, and to provide an object having such an antireflection coating.
• the coating comprises at least one antireflection coating in which the antireflection coating is prepared by a sol-gel process and the antireflection coating is a porous antireflection coating
• the porous antireflection coating comprises a metal or metal mixed oxide, in particular a zirconium oxide, tin oxide, aluminum oxide and / or mixed oxides of the above oxides, in particular, a silicon-aluminum mixed oxide, and is thus formed in spite of their porosity in an unexpectedly surprising manner mechanically stable and resistant.
• the invention provides a method for producing an article comprising at least one coating and one substrate, in which the coating comprises at least one antireflection coating in which the antireflection coating is produced by a sol-gel process, and the antireflection coating is a semimetal or metal oxide or semi-metal or mixed metal oxide, in particular an aluminum oxide or a silicon-aluminum mixed oxide.
• a hydrophobic substance is applied at least to a region of the antireflection coating and / or introduced into a region of the antireflection coating, thereby surprisingly effectively avoiding a deterioration of the optical properties of the antireflection coating, thus an increase in the reflectivity.
• an antireflection coating is understood to be a coating which, at least in a part of the visible, ultraviolet and / or infrared spectrum of electromagnetic waves, causes a reduction in the reflectivity at the surface of a substrate coated with this coating. In particular, this should increase the transmitted portion of the electromagnetic radiation.
• a hydrophobic substance is applied at least to a region of the antireflection coating and / or into a region of the antireflection coating It indicates that the hydrophobic substance can be applied to a region of a substrate already provided with an antireflection coating, introduced into the surface of its already applied antireflection coating or applied to the substrate together with an antireflection coating In this way, the porous antireflection coating is already provided with a certain inherent hydrophobicity, so that overall a particularly good hydrophobic effect can be achieved.
• the hydrophobic substance may additionally complicate the adhesion of liquids, which often carry dirt particles with it, and also facilitates the rinsing of impurities, especially of water-soluble impurities, since at contaminated sites by, for example, weather-related water input first loosening of pollution and then drainage
• the dissolved pollution is effected when the hydrophobic substance can act not only in the pores but also on the outwardly facing parts of the surface. Since thermal solar collectors, photovoltaic modules, roofs and walls of conservatories or greenhouses and in architectural glazing is usually not a horizontal orientation, this self-cleaning effect, especially on the otherwise slightly polluting outer surfaces of great advantage.
• At least partially verifying and antireflective effect can also be applied to the color-imparting to the layer.
• the antireflection coating advantageously comprises a porous antireflection coating or, as a monolayer antireflection coating, it consists of the porous coating
• Antireflection coating in the pores of the hydrophobic substance, in particular as a coating and preferably as a full-surface inner coating is applied.
• the incorporation of moisture, water or the adhesion of liquids in the region of the pores is surprisingly effectively reduced.
• changes in the refractive index of such porous layers, even in the damp-proof or outdoor areas, are greatly alleviated.
• hydrophobic substances already in the sol-gel binder which survive the process of penetration and thermal solidification.
• organic modified silanes such as triethoxymethylsilane or phenylsilane.
• the resulting hydrophobic layers are characterized in particular by a comparison with other organically modified or hydrophobic silanes high temperature stability.
• the or a further hydrophobic substance in the sol-gel process as a component of the sol-gel binder as a component of the sol-gel binder, in particular a silica sol submitted.
• hydrophobic substance may thereby comprise at least one organically modified silane, which has at least one bonded to Si methyl group and / or at least one bonded to Si phenyl group, in particular triethoxymethylsilane and / or phenylsilane.
• the antireflection coating contains porous nanoparticles having a particle size of about 2 nm to about 20 nm, preferably about 5 nm to about 10 nm, particularly preferably about 8 nm.
• the antireflection coating may also contain substantially non-porous nanoparticles, in particular having a particle size of about 2 nm to about 20 nm, preferably about 5 nm to about 10 nm, particularly preferably about 8 nm, which are arranged in such a way that by the distances between regions of adjacent particles is formed a porous structure.
• the substrate is made of glass or glass, this can also be thermally biased after the coating and thus thermally cured, without thereby the coating takes noticeable damage.
• Preferably is thermally cured by at least the to 6 minutes to be hardened region of the glass for a period of about 2 min, preferably 4 min, to a temperature of about 600 0 C to about 75O 0 C, preferably to a temperature of about 670 0 C is brought. If an activation of the surface of the substrate takes place before the application of the sol-gel layer, the adhesion of the applied layer can thereby be improved.
• the activation by corona discharge, • flame treatment, UV treatment, plasma activation and / or mechanical methods, as graining, sand blasting, and / or chemical processes are carried out as etching.
• one or more of the gas or liquid phase adhesion promoter layers can be applied to further increase the activation or, alternatively, the adhesion of the applied layer.
• hydrophobic substance for a period of about 2 min to about 2 h, preferably for about 1 h, heated to about 5O 0 C to about 450 0 C, most preferably to about 150 0 C, as this still remaining Remains of the order of the hydrophobic substance can be expelled and thus the desired ' reflectance of the layer is obtained.
• the hydrophobic layer is preferably no temperatures above assumes 300 ° C, temperatures are particularly preferred in these processes maintained below 200 0 C.
• the hydrophobic substance with a layer thickness of approximately at least partial coverage becomes advantageous a molecular monolayer up to about 200 nm, preferably of about this molecular monolayer up to about 130 nm and comprises, a substance which is selected from the group consisting of silanes, preferably fluoroalkylsilanes, chloroalkylsilanes, hydrocarbon compounds having at least one nonpolar radical, nonpolar Contains hydrocarbon compounds, silicones and mixtures thereof or consists of these.
• Preferred silanes have the general formula
• a, a 'and b, b' independently of one another have the value 0, 1 or 2 and
• n and m are independently an integer from 0 to 20 and together yield a maximum of 30 and
• R is a straight-chain, branched, saturated or unsaturated, optionally heteroatoms, Ci- to Ce- alkyl radical.
• alkyl radicals include methyl, ethyl and / or propyl radicals and / or their amino derivatives.
• Articles produced according to the method have at least one antireflection coating, preferably a single-layer antireflection coating, with a porous ceramic Nanoparticle coating whose pores are at least partially coated with a hydrophobic layer, in particular lined, in which the porous ceramic nanoparticles SiO ⁇ and Al 2 O 3 include.
• Ceramic nanoparticles having a particle size of about 2 nm to about 20 nm, preferably about 5 nm to about 10 nm, more preferably about 8 nm, is advantageously achieved that the transmission and reflection properties of the layer or the layer system by scattering only little to be worsened.
• the hydrophobic substance forms a layer having a layer thickness ranging from about one molecular monolayer to about 20 nm, the impact on the optical design of the layer or layer system remains relatively low, so that layer designs do not essentially have to be changed.
• the optical design of the layer or of the layer system can generally only with a change in the layer thickness of be taken over with the hydrophobic substance provided layer. This can be done in first order, the change in this layer thickness be made so that the changed by the hydrophobic substance optical path length in the layer is compensated by the layer thickness change. Preferably, this compensation is made for a central spectral range and perpendicularly incident light.
• the substrate preferably comprises a glass substrate, which may be a soda lime glass, for example Schott B270, and / or a borosilicate glass.
• a glass substrate which may be a soda lime glass, for example Schott B270, and / or a borosilicate glass.
• the surface of the glasses to be coated can be structured in order to thereby assist, in particular also for obliquely incident light, an increased passage through the glass and thus to increase the efficiency with solar energy generation.
• a low-iron or iron-free glass in particular with a F ⁇ 2 ⁇ 3 content less than 0.05% by weight, preferably less than 0.03% by weight can be used, as this has reduced absorption and thus enables a higher efficiency, especially when using solar energy.
• the glass substrate is a quartz glass.
• the object is part of a cover of solar thermal collectors or part of a cover of photovoltaic modules.
• the invention thus also relates to the use of the article as part of a device such as solar thermal collectors, covers of photovoltaic modules or other devices mentioned below.
• part of one here means that the object can be both the whole part itself or even a part includes: so for example, a part of a cover, such as the sun-directed top cover or only part of this can form or a can cover full-surface all-round coverage.
• the object may be part of a display and, in particular, part of an instrument glazing in a motor vehicle or an aircraft, since in addition to the long-term antireflection coating, fog-reducing properties are also added.
• these positive attributes can be useful when the object frequently changing temperatures, for instance as part of a refrigeration appliance, in particular as part of a viewing window of a refrigerator or a freezer exposed, is' t.
• the fog-reducing and long-term stable effect of the invention can be of great advantage.
• the good thermal resistance of the object may also be part of an attachment plate for lamps and lighting, in particular for architectural lighting or for motor vehicle headlights. Also with these Applications, the fog-reducing and improved self-cleaning effect can be of great advantage.
• the spectrum of possible uses widens if the object is part of a coloring layer in which the coloring can be effected either by incorporation of pigments or by the optical design of the single layer or of the layer system.
• FIG. 2 a long-term test after the application of a hydrophobic substance
• FIG. 3 a tabular representation of the mechanical and chemical stability of the antireflection coating.
• the method according to the invention makes it possible to provide articles, in particular different types of glasses, with at least one mechanically and chemically stable antireflection coating.
• Sol-gel methods for application, in particular also for large-area application, of the porous antireflective coating or of a porous material have to be used for manufacturing purposes
• Antireflective coating system proven in which by a metal or metal mixed oxide in the sol-gel layer, in particular by an aluminum oxide or a silicon-aluminum mixed oxide whose mechanical resistance and also their chemical resistance is significantly increased .
• the anti-reflection layer is almost completely resistant to water absorption and retains its favorable optical properties permanently.
• inorganic-organic hybrid polymers are used, which are known for example under the brand ORMOCER ® the Fraunhofer Institute for Silicate Research. In this case, however, it should be prevented that the respective pores are completely filled by the layer formers in the hydrophobic substances.
• sol-gel binder in particular the silica sol
• a hydrophobizing silane precursor which enables the production of temperature-stable layers.
• porous layers are obtained in which the surfaces are already covered with a certain amount of hydrophobic groups, so that water is not or clearly penetrate less than would be possible without this addition.
• An additionally applied hydrophobic substance then increases the total water repellency of the layer.
• Ein legientaptaungssysteme is limited, can be achieved with these already a broadband anti-reflection, which also shows over a wide angle of incidence high anti-reflection effect.
• a single porous anti-reflection coating for example on soda-lime glass or borosilicate glass, a significant reduction in the reflections in the visible wavelength range of light, 380 to 780 nm or else for the spectrum of solar radiation in the range from 300 to about 2500 nm can be achieved become.
• the preferred water-repellent porous monolayer anti-reflective coating is applied to a substrate comprising a soda-lime glass, for example Schott AG glass B270, a borosilicate glass, a quartz glass, an iron-free flat glass or a similar transparent article which is, for example, a thermally stable plastic can, upset.
• a soda-lime glass for example Schott AG glass B270, a borosilicate glass, a quartz glass, an iron-free flat glass or a similar transparent article which is, for example, a thermally stable plastic can, upset.
• this antireflection coating can also be applied to glass ceramics, such as, for example, thermal protection glasses, owing to their temperature resistance.
• the substrate may be of different shape. Thus, both the use of flat as well as tubular or rod-shaped substrates is possible.
• the porous layer comprises porous nanoparticles having a particle size of about 2 nm to about 20 nm, preferably about 5 nm to about 10 nm, more preferably about 8 nm.
• a preferred embodiment of the invention comprises a layer of porous nanoparticles, in which the
• Volume fraction of pores is 10% to 60% of the total volume of the layer. In this area of porosity, optimal results in reflection reduction are generally achieved.
• porous nanoparticles of the antireflection coating are applied to the substrate in the sol-gel process, which can be carried out as a spraying process, dipping process, wiping process, a coating or rolling process and / or Räkelvin.
• a reaction of metal-organic starting materials in the dissolved state is utilized for the formation of the layers.
• a metal oxide network structure is formed, i. a structure in which the metal atoms are linked together by oxygen atoms, along with the elimination of reaction products such as alcohol and water.
• reaction products such as alcohol and water.
• the substrate or article in the sol-gel coating, is withdrawn from the solution at a pulling rate of about 200 mm / min to about 450 mm / min, preferably about 300 mm / min, the moisture content of the atmosphere between about 4 g / m 3 and about 12 g / m 3 , more preferably about 8 g / m 3 .
• the sol-gel coating solution is to be used or stored for an extended period of time, it is advantageous to stabilize the solution by adding one or more complexing agents. These complexing agents must be soluble in the dipping solution and should be used in an advantageous manner with the solvent of the dipping solution. Preference is given to organic solvents which simultaneously have complex-forming properties, such as, for example, methyl acetate, ethyl acetate, acetylacetone,
• Acetoacetic ester, ethyl methyl ketone, acetone and similar compounds are added to the solution in amounts of 1 to 1.5 ml / l.
• the solution for producing the porous layer contains about 0.210 mol to about 0.266 mol, preferably about 0.238 mol of silicon, about 0.014 mol to about 0.070 mol, preferably about 0.042 mol of aluminum, about 0.253 mol to about 0.853 mmol, preferably about 0.553 mmol of HNO 3 , about 5.2 mmol to about 9.2 mmol, preferably about 7.2 mmol acetylacetone and at least one lower-chain alcohol.
• the acetylacetone surrounds the triply charged aluminum ions and creates a protective cover.
• nitric acid In addition to the nitric acid, other acids are suitable, such as hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, boric acid, formic acid or oxalic acid.
• porous mixed oxide layers are not only chemically resistant and mechanically extremely resistant but also lead to a drastic increase in the transmission of the layer or of the layer system on the substrate.
• thermally stable glasses such as.
• borosilicate glasses can increase the temperature and thus shorten the heating time.
• Borosilicate glasses can be baked at a reduced time at temperatures up to 900 c C and quartz or quartz glasses at temperatures above 1100 C 0 .
• Aluminum-silicon mixed oxide layer no crystals but a network that is amorphous to the smallest dimensions. Due to the stability of the porous network, it is possible to provide the substrates provided with the porous aluminum-silicon mixed oxide layer or Thermally bias glass substrates to achieve a mechanical hardening or stabilization of the coated article.
• the substrate with the porous layer thereon at a temperature of about 600 0 C to about 75O 0 C, preferably at about 670 0 C over a period of about 2 min to 6 min, preferably from 4 min thermally hardened or thermally toughened the glass.
• a temperature of about 600 0 C to about 75O 0 C preferably at about 670 0 C over a period of about 2 min to 6 min, preferably from 4 min thermally hardened or thermally toughened the glass.
• the surface of the article is activated prior to coating with the sol-gel layer.
• Such activation methods include oxidation, corona discharge, flame treatment, UV treatment, plasma activation and / or mechanical processes such as roughening, sandblasting, as well as plasma treatments or treatment of the substrate surface to be activated with acid and / or alkalis.
• Adhesion promoters include silanes and silanols having reactive groups.
• a hydrophobic substance initially present in liquid form or dissolved in a solvent is applied to the substrate coated with the porous antireflection coating by processes such as, for example, drainage, capillary technique, spin coating, spraying or dipping.
• the hydrophobic substance can be applied to the substrate in a wiping process, a coating or rolling process and / or by a doctor blade method.
• porous anti-reflection layer should be solidified prior to coating with the hydrophobic substance so that it no longer leads to flow disturbances, such as a zone-wise contraction of the
• Coating comes. By applying the hydrophobic solution to the porous antireflection coating, intensive penetration, coating and crosslinking of the hydrophobic substance with the porous antireflection coating can take place.
• the preferred hydrophobic components or components of the hydrophobic substance comprise at least one member of the group which contains or consists of silanes, preferably fluoroalkylsilanes, chloroalkylsilanes, hydrocarbon compounds having at least one nonpolar radical, nonpolar hydrocarbon compounds, silicones and mixtures thereof.
• silanes have the general formula
• a, a 'and b, b' independently of one another have the value 0, 1 or 2 and
• n and m are independently an integer from 0 to 20 and together yield a maximum of 30 and
• R is a straight-chain, branched, saturated or unsaturated (optionally heteroatom-containing) Ci- to Cg-alkyl radical.
• Preferred alkyl radicals are methyl, ethyl and propyl radicals, and their amino derivatives.
• Silanes are preferred which contain halogen atoms or halogen-comprising groups, such as For example, contain end or intermediate CF 2 - and CF 3 - groups, which increase or mediate the hydrophobic properties of the silane.
• the inventive antireflection coating is somewhat less hydrophobic after heating on its surface.
• the hydrophobic substance with its hydrophobic groups are bound to the surface of the pores, preferably even occupying them as full-flattened inner coating, the inner surface of the pores is protected in a surprisingly effective manner against water absorption in a surprisingly effective manner.
• Antireflective coatings is greatly reduced or even substantially no longer takes place.
• the process parameters of the sol-gel process in particular by adjusting the spray parameters and the course and drying time of the porous anti-reflection layer are adjusted so that both layers can be applied in a spray passage with two spray heads.
• the water-repellent porous monolayer antireflection coating according to the invention has been largely resistant to water absorption and storage for a long time, as investigations by the inventors have shown.
• the inert top layer of the single-layer antireflective layer in contrast to the documents mentioned in the prior art, does not consist of crystals but of a network down to the smallest dimensions of porous particles.
• the layers obtained according to the process show only slight haze upon scattering on both sides of a low-iron glass and increase the solar AM 1, 5 transmission (Air Mass Transmission) to values> 9 ⁇ %.
• the D65-weighted visual reflection of the inventive article is in other than solar applications with a preferably blue reflection color in the case of double-sided coating even less than 1.5%.
• the present invention allows the production of anti-reflection coatings for installation in solar systems with a wider useable angle of incidence, which is not possible with hitherto available, multi-coated glass.
• the samples were subjected to the standardized Taber Abraser test, a more stringent alcohol scrub test and a Sidolin® scrub test.
• the coated disc is placed on a turntable, on which roll two friction belts, which are provided with a defined load.
• the sample is loaded twice by 500 grams.
• the wheels make about ten revolutions on the sample surface.
• the wheels cross a complete circle on the sample surface.
• the size of the surface tested here is 30 cm 2 .
• the resulting wear marks a pattern in the form of crossed arches. This ensures that essentially every angle of the test area is subjected to the test.
• Plastic stamp in this case had a diameter of about 20 mm.
• the die was loaded with a piece of felt at the point where it contacted the sample surface to pick up the wetting agent, in this case pure alcohol.
• Sidolin scrub test differs from the alcohol scrub test only in the wetting agent used. It was used to wet the felt piece sold under the brand name Sidolin ® Henkel detergent. This test was also carried out with one hundred strokes.
• sample is the antireflection coating according to the invention and a “conventional control coating” is a conventional antireflection coating.
• FIG. 3 shows a table with the results of the comparison tests between unstabilized and aluminum oxide-stabilized antireflection layers.
• the table also demonstrates the effect of the mechanical and chemical stabilization of the novel antireflection coating by doping it with aluminum oxide.
• FIG. 1 shows the reflectivity or the reflection characteristic of a preferred porous porous coating layer doped with Al 2 O 3 according to the invention as a function of the wavelength.
• FIG. 1 Plotted in FIG. 1 are the properties of four samples produced according to the invention:
• FIG. 2 shows the reflection characteristic of the porous coating layer doped with Al 2 O 3 according to the invention as a function of the wavelength. Plotted are the properties of 5 samples, which after a period of:
• FIG. 2 shows how long-term stable the porous antireflection coating of the invention is over storage in moist air. As can be seen from the identical graphs, almost no moisture or no water is embedded in the pores of the layer, which is very clearly evident from the substantially identical reflection properties.
• Preferred embodiments of the sol-gel process are illustrated by the example of the preparation of a sol for producing the mechanically stable antireflection coating.
• a first solution based on a silica sol with a nominal particle size of 8 nm is prepared.
• the final solution contains silicon in a concentration of about 0.28 mol / l and low-water ethanol as a solvent.
• an HNO 3 concentration of 60 mmol / l is set.
• a second solution is prepared which contains 0.28 mol / l of aluminum in the form of the hydrous chloride AlCl 3 -6 H 2 O.
• the solvent used is likewise low-water ethanol, to which 485 g of acetylacetone (2,4-pentanedione) are added per 100 l of ready-to-use solution.
• Dipping solutions produced in this way are stable for a long time and can be used over several months.
• Dipping solution prepared which is used for coating both sides of a carefully cleaned, 4 mm thick, preferably made of low-iron float glass with a surface to be coated 40 cm by 40 cm.
• the glass sheet is completely immersed in the dipping solution, left in the solution for 10 seconds and then withdrawn at a rate of about 300 mm / min.
• the coated glass sheet is then brought to a temperature of 430 0 C over a period of one hour and then thermally cured at 67O 0 C for a period of four minutes.
• the disk thus obtained shows a reflection characteristic as a function of the wavelength directly after cooling to room temperature, as shown in FIG. 1 for the curve provided with the reference numeral 1.
• Curves 2, 3 and 4 show the reflectivity of the above-mentioned further samples 2, 3 and 4.
• the layers thus obtained permanently show only slight turbidity due to scattering and increase the solar AM 1, 5 transmission to approximately 97%.
• Pores is achieved, the just cooled, provided on both sides with a porous SiO 2 layer with 15 mol% Al2O 3 soft glass disc immersed in a fluoroalkylsilane-containing solution for a period of about 10 s, left in this solution and then with a
• a silica sol mixed with a hydrophobicizing silane can be used. Such a sol is obtained, for example, by adding triethoxymethylsilane or phenylsilane to the silica sol described above. This SoI can then be used to produce the layer as described above.

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• 2005
  • 2005-04-28 DE DE102005020168A patent/DE102005020168A1/de not_active Withdrawn
• 2006
  • 2006-04-28 WO PCT/EP2006/003973 patent/WO2006114321A1/de active Application Filing

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