Normal pressure chemical vapor deposition process for producing photoactive coatings uses gas mixture containing precursor which is sprayed at speed such that gap between mixing in precursor and striking substrate is below 0.01 seconds

摘要

Chemical vapor deposition process which operates at normal pressures for production of photoactive coatings uses a gas mixture containing a precursor. The mixture has a temperature above 500[deg]C when it strikes the substrate (40). It is sprayed on to the substrate at a speed such that the gap between heating and/or mixing in the precursor and striking the substrate is less than 0.01 seconds. An independent claim is included for apparatus for carrying out the method comprising a spray head (30) with a heating coil (31) which heats the gas above 500[deg]C and an inlet (10) for precursor. The power applied to the coil and the dimensions of the spray head are adjusted so that the gap between mixing in the precursor and striking the substrate is less than 0.01 seconds.