Classifications

• • 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
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/60—Additives non-macromolecular
  • C09D7/61—Additives non-macromolecular inorganic
• • 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
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
  • C09D183/06—Polysiloxanes containing silicon bound to oxygen-containing groups
• • 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
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
• • 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
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
• • 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
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/80—Processes for incorporating ingredients
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D2518/00—Other type of polymers

Definitions

• the present invention relates to coating compositions containing cerium dioxide on the basis of hydrolyzable silanes containing epoxide groups, the articles coated therewith and their use.
• sol-gel process it is possible to convert alkoxides, e.g. Aluminum propolate or butanolate, using modified alkoxysilanes to produce materials that are suitable as coatings.
• alkoxides e.g. Aluminum propolate or butanolate
• modified alkoxysilanes to produce materials that are suitable as coatings.
• These sol-gel processes are essentially characterized in that a mixture of the starting components reacts to a viscous liquid phase by means of a hydrolysis and condensation process.
• This synthetic method forms an organically modified inorganic backbone that has an increased surface hardness compared to conventional organic polymers.
• a crucial disadvantage is that due to the high reactivity of the aluminum-containing component, it is not possible to achieve high storage stability (pot life).
• the layers obtained are still relatively soft compared to inorganic materials. This is due to the fact that the inorganic components in the system have a strong cross-linking effect, but because of their very small size, the mechanical components
• compositions suitable for metal surfaces as well as corresponding systems for hydrophilic coatings.
• the compositions are obtained by a process which comprises adding a particulate material selected from oxides, hydrated oxides, nitrides and carbides of Si, Al and B or transition metals and having a particle size in the range of 1 to 100 nm, preferably boehmite, and / or a preferably nonionic surfactant and / or an aromatic polyol to form at least one prehydrolyzed silicon compound with a residue which has an epoxy group and is bonded directly to Si.
• a high scratch resistance is achieved by combining the prehydrolyzed silicon compound with the particulate material.
• hydrophilic coatings are obtained, while by combining the prehydrolyzed silicon compound with an aromatic polyol, corrosion-inhibiting coatings can be obtained.
• fluorinated silanes can be used in the process to produce hydrophobic or oleophobic
• Coatings Lewis bases or alcoholates can be added as crosslinking catalysts or other hydrolyzable compounds.
• DE-OS 40 20 316 describes a lacquer based on hydrolyzable silanes which, after hardening, leads to abrasion-resistant and flexible coatings. It can be obtained by reacting one or more silicon compounds having an epoxy group with water, the molar ratio of water to hydrolyzable groups being from 1: 1 to 0.4: 1.
• silicon compounds having an epoxy group for example aluminum, titanium, zirconium, vanadium, tin, lead and boron, can also be used.
• Particularly suitable catalysts for curing the composition are tiary amines are suitable which cause the epoxy groups to crosslink at temperatures above 60 ° C.
• DE-OS 30 21 018 discloses a coating composition which contains a partially hydrolyzed condensation product of alkyltrialkoxysilanes, an organic carboxylic acid and an anionic fluorocarbon surfactant.
• the silanes used do not contain epoxy groups.
• the composition results in surface coatings with an abrasion-resistant surface as well as good transparency, heat resistance and adhesion to the base material as well as water resistance.
• US 5,134,191 discloses a hard coating composition which contains an organic silicon compound containing epoxy groups and inorganic submicron particles such as silica sol and is curable with a minimal amount of an antimony compound as a curing catalyst. It can be used as a coating film for optical plastic articles. If necessary, the composition can also contain an aluminum compound.
• DE-OS 43 38 361 discloses coating compositions which contain silicon compounds containing epoxy groups, nanoscale oxides or oxide hydrates of Si, Al, B or transition metals, with boehmite being preferred in particular, containing surfactants and aromatic polyols.
• the bases can additionally contain Lewis bases, alcoholates of titanium, zirconium or aluminum.
• the object of the present invention was to provide compositions with an even further improved resistance to hydrolysis, scratch resistance and UV stability.
• a coating composition containing (a) at least one silicon compound (A) which has at least one radical which cannot be split off hydrolytically and is bonded directly to Si and which contains an epoxy group,
• particulate boehmite (B) with a particle size in the range from 1 to 100 nm
• a Lewis base (F) can additionally be used as a catalyst.
• a hydrolyzable silicon compound (G) with at least one non-hydrolyzable radical can be used, for example dialkyldialkoxysilanes, preferably dimethyldimethoxysilane.
• the partial replacement of the silicon compound (D) by silicon compounds (G) reduces the hardness of the coatings obtained.
• a preferably non-ionic surfactant (G) can be used to achieve long-term hydrophilic properties and / or an aromatic polyol (H) can be used to achieve corrosion-inhibiting properties (increase in the resistance to condensation).
• the silicon compound (A) is a silicon compound which has
• hydrolyzable radicals 2 or 3, preferably 3, hydrolyzable radicals and one or 2, preferably one, non-hydrolyzable radical.
• the only or at least one of the two non-hydrolyzable residues has an epoxy group.
• hydrolyzable radicals examples include halogen (F, Cl, Br and I, in particular
• alkoxy in particular C -alkoxy, such as, for example, methoxy, ethoxy, n-propoxy, i-propoxy and n-butoxy, i-butoxy, sec-butoxy and tert-butoxy
• aryloxy in particular C 6 I0 aryloxy, for example phenoxy
• acyloxy in particular C-acyloxy, for example acetoxy and propionyloxy
• alkylcarbonyl for example acetyl
• Particularly preferred hydrolyzable radicals are alkoxy groups, especially methoxy and
• non-hydrolyzable radicals without an epoxy group are hydrogen, alkyl, in particular C ,. 4 alkyl (such as methyl, ethyl, propyl and butyl), alkenyl (especially C 2. 4, alkenyl groups such as vinyl, 1-propenyl, 2-propenyl and butenyl),
• Alkynyl especially C 1-4 alkynyl, such as acetylenyl and propargyl
• aryl especially C 6 .
• 10- aryl such as phenyl and naphthyl
• substituents such as halogen and alkoxy.
• Methacrylic and methacryloxypropyl radicals can also be mentioned in this connection.
• non-hydrolyzable radicals with an epoxy group are, in particular, those which have a glycidyl or glycidyloxy group.
• silicon compounds (A) which can be used according to the invention can be found, for example, on pages 8 and 9 of EP-A-195 493, the disclosure of which is incorporated by reference into the present application.
• Silicon compounds (A) which are particularly preferred according to the invention are those of the general formula
• radicals R are identical or different (preferably the same) and a hydrolyzable group (preferably C alkoxy, and especially methoxy and ethoxy) and R 'represents a glycidyl or glycidyloxy- (C ,.
• alkylene radical in particular ß-glycidyloxyethyl-, ⁇ -glycidyloxypropyl, ⁇ -glycidyl-oxy-butyl-, ⁇ -glycidyloxypentyl-, ⁇ -glycidyloxyhexyl-, ⁇ -glycidyloxyoctyl-, ⁇ -glycidyloxidyl, ⁇ -glycidyl-, ⁇ -glycidyl - And 2- (3,4-epoxy-cy clohexyl) ethyl.
• GPTS ⁇ -glycidyloxypropyltrimethoxysilane
• Particulate boehmite (B) is preferably used with a particle size in the range from 1 to 100, preferably 2 to 50 nm and particularly preferably 5 to 20 nm.
• This material can be used in the form of a powder, but is preferably used in the form of a (in particular acid-stabilized) sol. Nanoscale boehmite particles are particularly preferably used.
• Particulate boehmite is commercially available in the form of powders, and the production of (acid-stabilized) sols therefrom is also known in the prior art.
• Boehmite sol with a pH in the range from 2.5 to 3.5 is particularly preferred, before trains used 2.8 to 3.2, which can be obtained, for example, by suspending boehmite powder in dilute HC1.
• Particulate cerium oxide (C) is preferably used with a particle size in the range from 1 to 100, preferably 2 to 50 nm and particularly preferably 5 to 20 nm.
• This material can be used in the form of a powder, but is preferably used in the form of a (in particular acid-stabilized) sol.
• Particulate cerium oxide is commercially available in the form of sols and powders, and the production of (acid-stabilized) sols therefrom is also known in the art.
• hydrolyzable silicon compounds are also used to prepare the compositions according to the invention and are preferably hydrolyzed with the silicon compound (s) (A).
• the hydrolyzable silicon compound (D) is a compound of the general formula
• R represents a hydrolyzable radical
• R ' represents a non-hydrolyzable radical
• x can be 1 to 4. If several radicals R and / or R 'are present in a compound (D), these can in each case be the same or different.
• X is preferably greater than 1. Ie, the compound (D) has at least one, preferably several, hydrolyzable radicals.
• hydrolyzable radicals examples include halogen (F, Cl, Br and I, in particular Cl and Br), alkoxy (in particular C M alkoxy, such as methoxy, ethoxy, n-propoxy, i-propoxy and n-butoxy, i-butoxy, sec-butoxy or tert-butoxy), aryloxy (in particular C 6. ] 0 -aryloxy, for example phenoxy), acyloxy (in particular C,. 4 -acyloxy, for example acetoxy and propionyloxy) and alkylcarbonyl (for example acetyl) .
• Particularly preferred hydrolyzable radicals are alkoxy groups, especially methoxy and ethoxy.
• non-hydrolyzable radicals are hydrogen, alkyl, in particular C M - alkyl (such as methyl, ethyl, propyl and n-butyl, i-butyl, sec-butyl and tert-
• alkenyl especially C 2, 4- alkenyl, such as vinyl, 1-propenyl, 2-propenyl and butenyl
• alkynyl especially C 2, 4- alkynyl, such as acetylenyl and propargyl
• aryl in particular C 6 .
• 0- aryl, such as phenyl and naphthyl where the groups just mentioned may optionally have one or more substituents, such as halogen and alkoxy.
• substituents such as halogen and alkoxy.
• silicon compounds (D) that can be used are given below.
• CH 2 CH-Si (OOCCH 3 ) 3
• CH 2 CH-SiCl 3
• CH 2 CH-Si (OCH 3 ) 3
• CH 2 CH-Si (OC 2 H 5 ) 3
• CH 2 CH-Si (OC 2 H 4 OCH 3 ) 3
• CH 2 CH-CH 2 -Si (OCH 3 ) 3
• CH 2 CH-CH 2 -Si (OC 2 H 5 ) 3
• CH 2 CFI-CH 2 -Si (OOCCH 3 ) 3
• CH 2 C (CH 3 ) -COO-C 3 H 7 -Si ( OCH 3 ) 3
• CH 2 C (CH 3 ) -COO-C 3 H 7 -Si (OC 2 H 5 ) 3
• radicals R can be identical or different and stand for a hydrolyzable group, preferably for an alkoxy group with 1 to 4 carbon atoms, in particular for methoxy, ethoxy, n-propoxy, i-propoxy, n- Butoxy, i-butoxy, sec-butoxy or tert-butoxy.
• the compound (E) is preferably a compound of AI of the following general formula
• radicals R '" can be the same or different and stand for a hydrolyzable group.
• hydrolyzable groups examples include halogen (F, Cl, Br and I, in particular Cl and Br), alkoxy (in particular. C,. 6 -alkoxy, such as, for example, methoxy, ethoxy, n-propoxy, i-propoxy and n-butoxy , i-butoxy, sec-butoxy or tert-butoxy, n-pentyl oxy, n-hexyloxy), aryloxy (especially C sixth I0 aryloxy, such as phenoxy), acyloxy (especially C M acyloxy, such as acetoxy, and Propionyloxy) and alkylcarbonyl
• halogen F, Cl, Br and I, in particular Cl and Br
• alkoxy in particular. C,. 6 -alkoxy, such as, for example, methoxy, ethoxy, n-propoxy, i-propoxy and n-butoxy , i-butoxy, sec-butoxy or tert-but
• R '"ethanolate, sec-butanolate, n-propanolate or n-butoxyethanolate is particularly preferred.
• hydrolyzable aluminum compounds (E) which can be used according to the invention are Al (OCH 3 ) 3 , Al (OC 2 H 5 ) 3 , Al (OnC 3 H 7 ) 3 , Al (OiC 3 H 7 ) 3 , Al (OC 4 H 9 ) 3 , Al (OiC 4 H 9 ) 3 , Al (O-sek-C 4 H 9 ) 3 , A1C1 3 , AlCl (OH) 2 , Al (OC 2 H 4 OC 4 H 9 ) 3 .
• the Lewis base (F) is preferably a nitrogen compound.
• nitrogen compounds can e.g. selected from N-heterocycles, amino group-containing phenols, polycyclic amines and ammonia (preferably as an aqueous solution).
• nitrogen compounds can e.g. selected from N-heterocycles, amino group-containing phenols, polycyclic amines and ammonia (preferably as an aqueous solution).
• Specific examples of this are 1-methylimidazole, 2- (N, N-dimethylaminomethyl) phenol, 2,4,6-tris (N, N-dimethylaminomethyl) phenol and 1,8-diazabicyclo [5.4.0] - 7-undecen.
• 1-methylimidazole is particularly preferred.
• Another class of nitrogen-containing Lewis bases which can be used according to the invention are hydrolyzable silanes which have at least one non-hydrolyzable radical which comprises at least one primary, secondary or tertiary amino group.
• Such silanes can be hydrolyzed together with the silicon compound (A) and then constitute a Lewis base built into the organically modified inorganic network.
• Preferred nitrogenous ones are hydrolyzable silanes which have at least one non-hydrolyzable radical which comprises at least one primary, secondary or tertiary amino group.
• Silicon compounds are those of the general formula
• radicals R are identical or different (preferably identical) and stand for a hydrolyzable group (preferably C M - alkoxy and in particular methoxy and ethoxy), and R "stands for a non-hydrolyzable radical bound to Si, which is at least one primary , secondary or tertiary amino group
• silanes are 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- [N '- (2'-Aminoethyl) -2-aminoethyl] 3-aminopropyltrimethoxysilane and N- [3- (triethoxysilyl) propyl] -4,5-dihydroimidazole.
• the Lewis base is generally used in the corresponding compositions in an amount of from 0.01 to 0.5 mol per mol of epoxy group of the silicon compound (A). Amounts in the range from 0.02 to 0.3 and in particular 0.05 to 0.1 mol of Lewis base per mol of epoxy group are preferred.
• the surfactant (G) which can be used to achieve a long-term anti-fogging effect and to increase the hydrophilicity of the coatings, is preferably a nonionic surfactant.
• Nonionic surfactants which are in liquid form at room temperature are particularly preferred. It is not only possible to use these surfactants during the preparation of the compositions by the process according to the invention, but they can also be thermally diffused in subsequently (preferably in aqueous solution) at about 50 to 60 ° C.
• Preferred surfactants are polyoxyethylene oleyl ethers of different chain lengths (e.g. Brij® 92, 96 or 98 from ICI), polyoxyethylene cetyl ethers of different
• Chain length (e.g. Malipal® 24/30 to 24/100 from Huls and Disponil® 05 from Henkel), sodium lauryl sulfate (e.g. Sulfopon® 101 Special from Henkel), lauryl pyridinium chloride (e.g. Dehydquad C Christ® from Fa . Henkel) and polyoxyethylene sorbitan monooleate (eg Tween® from Riedel de Haen).
• sodium lauryl sulfate e.g. Sulfopon® 101 Special from Henkel
• lauryl pyridinium chloride e.g. Dehydquad C Christ® from Fa . Henkel
• polyoxyethylene sorbitan monooleate eg Tween® from Riedel de Haen
• the surfactant is generally used in amounts of 0.1 to 35% by weight, based on the coating composition.
• Aromatic polyol (H) is generally used in amounts of 0.1 to 35% by weight, based on the coating composition.
• the aromatic polyol used according to the invention has an average molecular weight of at most 1000.
• examples of such polyols are, for example, polyphenylene ethers which carry hydroxyl groups on at least 2 of the phenyl rings, and oligomers in which aromatic rings are bonded to one another by a single bond, -O-, -CO-, -SO 2 - or the like and at least (and preferably ) 2 have hydroxyl groups bonded to aromatic groups.
• Aromatic diols are particularly preferred aromatic polyols. Among these, particular preference is given to compounds having the following general formulas:
• X is a (C r C 8 ) alkylene or alkylidene radical, a (C 6 -C ] 4 ) arylene radical, -O-, -S-, -CO- or -SO 2 - and n is 0 or 1 is.
• XC, -C 4 -alkylene or alkylidene, in particular -C (CH 3 ) 2 -, and -SO 2 - is preferred.
• the aromatic rings of the compounds can also carry up to 3 or 4 further substituents, for example halogen, alkyl and alkoxy.
• aromatic polyols (H) which can be used according to the invention are bisphenol A, bisphenol S and 1,5-dihydroxynaphthalene, bisphenol A is preferred.
• the polyol (H) is generally used in amounts such that 0.2 to 1.5 mol, preferably 0.3 to 1.2 and particularly preferably 0.6 to 1.0 mol of hydroxyl groups per mol of epoxy ring of the silicon compound (A) of aromatic polyol (H) are present.
• the use of silicon compounds (A) which have at least two epoxy groups in the compositions according to the invention leads to coatings and moldings with improved condensation stability.
• compositions according to the invention are preferably obtained by a process described in more detail below, in which a sol of material (B) having a pH in the range from 2.5 to 3.5, preferably 2.8 to 3.2, with a mixture of the others Components is implemented.
• sols are even more preferably produced by a process which is also defined below, in which the sol as defined above is added in two portions to the mixture of (A) and (D), with certain temperatures preferably being maintained, and the addition of (E ) between the two portions of (B), also preferably at a certain temperature.
• the hydrolyzable silicon compound (A) can optionally be prehydrolyzed together with the compound (D) using an acidic catalyst (preferably at room temperature) in aqueous solution, preferably using about 1/2 mole of water per mole of hydrolyzable group.
• Hydrochloric acid is preferably used as the catalyst for the pre-hydrolysis.
• the particulate boehmite (B) is preferably suspended in water and the pH is adjusted to 2.5 to 3, preferably 2.8 to 3.2. Hydrochloric acid is preferably used for acidification. A clear sol forms under these conditions.
• the compound (D) is mixed with the compound (A).
• the first portion of the particulate boehmite (B) suspended as described above is then added.
• the amount is preferably chosen so that the water contained therein is sufficient for the semi-stoichiometric hydrolysis of the compounds (A) and (D).
• a few minutes after the addition the sol warms up to about 28 to 35 ° C and is clear after about 20 minutes.
• the mixture is then stirred for 0.5 to 3 hours, preferably 1 to 2 hours.
• the batch is cooled to approx. 0 ° C.
• the compound (E) is then added, a temperature of about 3 ° C. should not be exceeded.
• the sol is stirred at 0 ° C. for 0.5 to 3 hours, preferably 1 to 2 hours.
• the remaining particulate material (B) is added, the temperature should not exceed 5 ° C.
• the reactor temperature is then set to 20 ° C. in order to bring the composition to room temperature.
• a room temperature is understood to be a temperature of 20 to 23 ° C.
• Compound (C) is preferably added at this point in time for UV stabilization of the scratch-resistant coating system.
• Compound (C) is preferably in the form of a sol.
• the composition is stored in the refrigerator at 4 ° C.
• the compound (E) and optionally the Lewis base (F) are preferably added slowly after addition of the first portion of the material (B) also at 0 ° C.
• inert solvents may optionally be added at any stage of manufacture.
• These solvents are preferably alcohols which are liquid at room temperature and which, moreover, also result from the hydrolysis of the alkoxides which are preferably used.
• Particularly preferred alcohols are C.I. 8 alcohols, especially methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, tert-
• compositions according to the invention can furthermore contain customary additives, such as, for example, dyes, leveling agents, UV stabilizers, photoinitiators, photosensors. sibilizers (if photochemical curing of the composition is intended) and thermal polymerization catalysts.
• Application to the substrate is carried out using standard coating processes such as Dipping, brushing, brushing, knife coating, rolling, spraying, falling film application, spin coating and spinning.
• the coated substrate is cured.
• the curing preferably takes place thermally at temperatures in the range from 50 to 300 ° C., in particular 70 to 200 ° C. and particularly preferably 90 to 180 ° C., if appropriate under reduced pressure. Under these conditions, the curing time should be less than 200 minutes, preferably less than 100 minutes and more preferably less than 60 minutes.
• the layer thickness of the hardened layer should be 0.5 to 100 ⁇ m, preferably 1 to 20 ⁇ m and in particular 2 to 10 ⁇ m.
• curing can also be carried out by irradiation, which may be followed by thermal post-curing.
• compositions according to the invention are preferably suitable for coating wood, textiles, paper, stone goods, metals, glass, ceramics and plastics, and in particular are suitable for coating thermoplastics, as described in Becker / Braun, Kunststoff Taschenbuch, Carl Hanser Verlag, Kunststoff, Vienna 1992 are.
• compositions are particularly suitable for coating transparent thermoplastics and preferably polcarbonates or for coating metals or metallized surfaces.
• Spectacle lenses, optical lenses, automotive lenses and thermal heads in particular can be coated with the compositions obtained according to the invention. Examples
• boehmite dispersion 0.1 N hydrochloric acid is introduced to prepare the boehmite dispersion. Boehmite is then slowly added while stirring. The dispersion is then sonicated for about 20 minutes.
• GPTS and TEOS are submitted and mixed. While stirring, slowly pour in the amount of boehmite dispersion necessary for the semi-stoichiometric pre-hydrolysis of the silanes. The reaction mixture is then stirred at RT for 2 h. The solution is then cooled to 0 ° C using a thermostat. Aluminum tributoxyethanolate is then added dropwise via a dropping funnel.
• the mixture is stirred at 0 ° C. for 1 h. Then the rest of the boehmite dispersion is added under thermostatic cooling. After stirring for 15 minutes at room temperature, the cerium dioxide dispersion and leveling agent are added.
• the coated samples (with Makrolon 2808 as substrate) are placed in a Suntest (type: Heraeus CPS) with a quartz glass filter at maximum performance for 3 weeks. After one, two and three weeks, the yellow value by means of UV / Nis spectroscopy (parameters: standard light C, 2 ° normal observer). There is also an optical assessment of the samples (cracking, etc.).
• a glass desiccator filled with deionized water is placed in a drying cabinet, the temperature of which is approx. 65 ° C. After tempering, the coated polycarbonate samples, with which a cross-cut / wallpaper test has previously been carried out, are placed in the desiccator. After 2, 4, 6, 8, 10, 12 and 14 days, the samples are examined for their adhesion using a cross-cut / wallpaper test. For this purpose, the original cross-cut is examined and a completely new cross-cut / wallpaper test is carried out. In addition, the samples are assessed optically (cracking, detachment ).
• the vessel is isolated using a polystyrene coating and the water is brought to a boil using a magnetic heating stirrer (temperature approx. 97 ° C). Then the samples (coated polycarbonate), which have been examined beforehand using a cross-cut / wallpaper test, are added. After 1, 2, 3, 4, 5, 6, 7 and 8 h, the panels are removed and visually assessed (cracks, detachment, etc.).
• Layer thickness determination The layer thickness is determined profilometrically using a fine diamond needle that is guided over the surface. To determine this, it is necessary to mask part of the plate during painting in order to verify the difference in height between the uncoated and coated area. Table 1

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• 1998
  • 1998-12-21 DE DE19858998A patent/DE19858998A1/de not_active Withdrawn
• 1999
  • 1999-12-14 AU AU24315/00A patent/AU2431500A/en not_active Abandoned
  • 1999-12-14 BR BR9916374-8A patent/BR9916374A/pt not_active Application Discontinuation
  • 1999-12-14 EP EP99967937A patent/EP1141152A1/de not_active Withdrawn
  • 1999-12-14 KR KR1020017007790A patent/KR20010099852A/ko not_active Application Discontinuation
  • 1999-12-14 IL IL14320899A patent/IL143208A0/xx unknown
  • 1999-12-14 CN CN99814835A patent/CN1331732A/zh active Pending
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