METHOD FOR MAKING AN ABSORBER COATING FOR SOLAR HEATING, THE COATING AS SUCH AND ITS APPLICATION

摘要

Method for making an absorber coating for solar heating and a coating as such to be applied on a metal substrate, in particular a coating to be applied on a thin aluminium metal sheet. The coating is of the sol-gel type based on a metal oxide precursor where pigment particles are intimately mixed into the precursor followed by application of the mixed sol lacquer on the substrate and thereafter reaction in humid air at a required temperature to obtain the sol-gel coating. The precursor may preferably be a CeO2 (NO3) based sol with preferably 20 % CeO2 having a particle size of 10- 20 nm and a pH of 1,5. Further the pigment may be a manganese ferrite black spinel, Mn3Cu2FeO8.