Method for coating surfaces with particles and use of the coatings produced by this method

A process for the currentless coating of, in particular, metallic surfaces of objects, which can optionally be precoated, with a large number of at least one of inorganic water-insoluble particles or organic water-insoluble particles to form a substantially wash-resistant layer having a high particle density, in which the particles are applied to the surfaces to be coated in a stabilizable or stable aqueous composition in the form of a dispersion and are applied to and held on the surfaces to be coated substantially or predominantly by means of electrostatic forces, wherein

• the surfaces to be coated are first activated with an activating agent, wherein an activation layer with charges is formed with the activating agent on the surfaces to be coated, wherein these charges are charged oppositely to the charges of the particles of the composition which are subsequently to be applied,
• in that an activation layer is formed on the surface to be coated, which in the case of a cationic activation layer is produced by contacting with at least one cationic compound and which in the case of an anionic activation layer is produced by contacting with at least one anionic compound,
• in that at least one protonatable or protonated silane or at least one protonatable or protonated nitrogen-containing compound is/are used as the cationic compound(s) or in that at least one deprotonatable compound or at least one deprotonated anion or at least one deprotonatable and/or deprotonated anionic compound is/are used as the anionic compound(s)
• in that the particles applied in a coating step with a particle-containing composition are charged oppositely to the charges of the activation layer,
• in that anionically stabilized aqueous polymer particle dispersions or cationically stabilized aqueous polymer particle dispersions are used as particles,
• in that in a or in each coating step with a particle-containing composition in each case a layer is formed on the surfaces to be coated in an average thickness of several average particle sizes of the particles applied and the or each particle layer is optionally then formed into a film or crosslinked, as a result of which a layer thickness of the or each particle layer of particles which have not been formed into a film or of the coating which has been formed into a film or crosslinked produced therefrom in each case in the range of from 50 nm to 50 μm is achieved.