Method for preparing flexible mechanically compensated transparent layered material

A method for preparing a layered material comprising a transparent polymer foil carrier both sides of which are at least partly covered with one or more layers, the one or more layers comprising at least one layer of a transparent inorganic material in a compressive state, the method comprising the consecutive steps of:

• b) applying a transparent inorganic material layer over each of two temporary substrates of a metal or metal alloy foil at a temperature over 250° C., wherein the transparent inorganic material layers have a thermal expansion coefficient below a thermal expansion coefficient of the two temporary substrates;
• c) providing the transparent polymer foil carrier sandwiched between the transparent inorganic material layers on the two substrates,
• wherein, after cooling, the difference between the thermal expansion coefficient of the transparent inorganic material layers and the thermal expansion coefficient of the two temporary substrates results in a compressive state of the transparent inorganic material layers
• and wherein the one or more layers at both sides of the transparent polymer foil carrier mutually compensate mechanical stresses in the transparent polymer foil carrier induced by the compressive state;
• d) removing the temporary substrates.