Method for the production of composite materials with an antireflexion coating, comprises applying a barrier layer on a glass substrate against sodium ion diffusion and applying a single-layer antireflexion coating over the barrier layer

The method comprises applying a barrier layer on a glass substrate against sodium ion diffusion and applying a sodium-free porous single-layer antireflexion coating over the barrier layer against sodium ion diffusion, by sol-gel-process, where hydrolysis and/or condensation is carried in strong acid milieus. The single-layer antireflexion coating consists of sodium portion of less than 2500 ppm. The organic silicon compound is dosed in such a way that the portion of silicon from the organic silicon compound is 7-15% of the total portion of the silicon in the antireflexion coating. The method comprises applying a barrier layer on a glass substrate against sodium ion diffusion and applying a sodium-free porous single-layer antireflexion coating over the barrier layer against sodium ion diffusion, by sol-gel-process, where hydrolysis and/or condensation is carried out in strong acid milieus. The single-layer antireflexion coating consists of sodium portion of less than 2500 ppm, where both particles are added as also an organic silicon compound. The organic silicon compound is dosed in such a way that the portion of silicon from the organic silicon compound is 7-15% of the total portion of the silicon in the antireflexion coating. A metal oxide precursor or a suspension with silicon particles is added to the sol for hardening the antireflexion coating, which consists of aluminum oxide as curing agent. The antireflexion coating is free from elements of alkali- and/or alkaline earth metal group. The barrier layer is applied against sodium ion diffusion in a thickness of 10-35 nm. The pH-value during the hydrolysis and/or condensation is below 1.5. The barrier layer is applied by physical vapor deposition- or chemical vapor deposition process or flame pyrolysis. The antireflexion coating is burned during a thermal prestressing process. An independent claim is included for a composite material. Die Erfindung betrifft ein Verfahren zur Herstellung eines Verbundmaterials, wobei zwischen einer im Wesentlichen natriumfreien Entspiegelungsschicht und einem Substratglas eine Barriereschicht gegen Natriumionendiffusion angeordnet ist.