Light-transmitting substrate provided with a light-absorbing coating, light absorbing coating as well as method of preparing a light-absorbing coating

A light-absorbing coating comprising stabilized pigments which are incorporated in a sol-gel matrix, said light absorbing coating comprising silica particles having a size between 5 and 100 nanometers and alumina particles having a size between 5 and 50 nanometers, wherein the total volume concentration of pigments, silica and alumina particles in the light-absorbing coating is between 20 and 65 per cent, the volume concentration of silica particles between 5 and 40 per cent and the volume concentration of alumina particles between 1 and 15 per cent.

A method of preparing a light absorbing coating, said method at least comprising the steps of

• preparing a pigment dispersion by mixing a pigment with an alcohol-comprising liquid
• preparing a hydrolysis mixture comprising a silane wich is subjected to a sol-gel process, said hydrolysis mixture further comprising silica particles having a size between 5 and 100 nanometers and alumina particles having a size between 5 and 50 nanometers
• mixing the pigment dispersion and the hydrolysis mixture in such a way that the total volume concentration of pigments, silica and alumina particles in the light-absorbing coating is between 20 and 65 per cent, the volume concentration of silica particles between 5 and 40 per cent and the volume concentration of alumina particles between 1 and 15 per cent.