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
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D1/00—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
• • 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

Definitions

• Hydrophobic properties are sought after for side windows and windshields in the field of transport, in particular for motor vehicles, where it is essential, for obvious safety reasons, to optimize the transparency of the glazing even in the event of rain .
• Raindrops must cling as little as possible to the exterior surface of the glazing and, on the contrary, flow easily under the effect of gravity or aerodynamic flows.
• n 7 -15, we mean that n can take all integer values between 7 and 15, limits included.
• a primary layer on the surface to be treated preferably made of silica.
• this primary layer it is important that it contains as many active silanol (Si-OH) groups as possible, that is to say capable of reacting with the silanol groups released by the hydrolysis of the alkoxy functions of the alkyl-trialkoxy-silane or of the chlorine atoms of the alkyltrichlorosilanes.
• silica layer is sufficiently condensed before deposition of the acidic hydroalcoholic solution containing the alkyltrialkoxysilane and/or alkyltrichlorosilane. If the silica layer was insufficiently condensed, it could indeed be eliminated or damaged during the creation of the hydrophobic functional layer.
• step of forming the primary layer with a step of polishing the substrate, for example using a felt impregnated with an aqueous suspension of fine abrasive particles, followed by a rinsing with water and drying.
• the formation of the primary silica layer is done by a sol-gel step in which a tetrachlorosilane and/or a tetraalkoxysilane, preferably tetraethoxysilane, is hydrolyzed in an acidic hydroalcoholic medium.
• tetrachlorosilane or tetraalkoxysilane is dissolved in a water/alcohol mixture, typically a water/isopropanol mixture, the pH of the water having been previously adjusted to a value between 1 and 3.
• a water/alcohol mixture typically a water/isopropanol mixture
• the tetrachlorosilane and/or tetraalkoxysilane content of this hydroalcoholic solution is advantageously between 0.1 and 1% by weight, preferably between 0.15 and 0.8% by weight.
• the molar ratio of water to the silica precursor is generally between 400 and 600, preferably between 450 and 550 and in particular between 480 and 520.
• hydroalcoholic solution it is preferable not to apply the hydroalcoholic solution immediately after dissolution of the tetrachlorosilane and/or tetraalkoxysilane, but to allow the hydrolysis to take place at room temperature (20 – 25 °C) for a period of between 30 minutes and 4 hours. , preferably between 40 minutes and 3.5 hours, especially between 45 minutes and 3 hours. During this time, it is recommended to stir the solution to ensure good homogeneity of the reaction medium. It is generally not necessary to add thermal energy to the solution during this hydrolysis step.
• the acidic hydroalcoholic solution of tetraalkoxysilane or tetrachlorosilane can be applied in principle by any technique allowing the formation of a thin liquid film on the surface of the substrate.
• spraying, or nebulization, and application using a cloth soaked in the hydroalcoholic solution of tetraalkoxysilane or tetrachlorosilane will be used.
• the liquid film formed is allowed to dry for a period of at least 5 minutes, preferably at least 15 minutes.
• the silica primer layer advantageously has a thickness of between 5 nm and 250 nm, preferably between 10 nm and 100 nm, in particular between 15 nm and 75 nm.
• the step of grafting the alkyltrialkoxysilane and/or the alkyltrichlorosilane is carried out, like the formation of the primary silica layer, by a sol-gel step in which the alkyltrialkoxysilane and/or the alkyltrichlorosilane is hydrolyzed in a medium hydroalcoholic acid. It can be implemented in a manner similar to that used for the formation of the primary layer, except that the grafting of the alkyltrialkoxysilane or the alkyltrichlorosilane is preferably done in a single application step.
• the grafting composition is an acidic hydroalcoholic (water/isopropanol) solution of (C 8 -C 16 alkyl)-trialkoxysilane and/or (C 8 -C 16 alkyl)-trichlorosilane.
• the hydroalcoholic solution of (C 8 -C 16 alkyl)-trialkoxysilane or (C 8 -C 16 alkyl)-trialkoxysilane is advantageously left at room temperature for a period of approximately 30 minutes to approximately 3 hours , preferably with stirring, to allow the hydrolysis of the (C 8 -C 16 alkyl)-trialkoxysilane or the (C 8 -C 16 alkyl)-trialkoxysilane, before being applied by spraying ( spray ), watering or wiping the glass substrate covered on one of its main faces with the primary layer of silica.
• (C 10 alkyl)-silane makes it possible to obtain hydrophobic glass substrates having particularly high durability of hydrophobic properties: resistance to salt corrosion greater than 14 days and UV resistance greater than 1000 hours.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Surface Treatment Of Glass (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Laminated Bodies (AREA)
• Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)

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• 2022
  • 2022-11-25 FR FR2212350A patent/FR3142384B1/fr active Active
• 2023
  • 2023-11-22 EP EP23809612.7A patent/EP4622932A1/de active Pending
  • 2023-11-22 JP JP2025530515A patent/JP2025540722A/ja active Pending
  • 2023-11-22 KR KR1020257018860A patent/KR20250114325A/ko active Pending
  • 2023-11-22 WO PCT/EP2023/082657 patent/WO2024110517A1/fr not_active Ceased
  • 2023-11-22 CN CN202380080933.3A patent/CN120265592A/zh active Pending

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