PROCESS FOR THE FORMATION OF HARD COAT AND PROCESS FOR THE PRODUCTION OF GRAVURE PRINTING ROLL

摘要

The invention provides a process for forming a hard coat having a satisfactorily high hardness on a substrate by using perhydropolysilazane as the raw material; and a process for the production of a gravure printing roll which has a nontoxic surface-reinforcing coat free from the anxiety about environmental pollution and is excellent in plate wear. A process which comprises the coating formation step of applying a solution of perhydropolysilazane to the surface of a substrate to form a coating having a prescribed thickness and the step of heat-treating the perhydropolysilazane coating with superheated steam under prescribed conditions to form a silicon dioxide coat on the surface of the substrate, wherein the heat-treatment is conducted in plural stages including the first and second heat-treatments and the first heat treatment is conducted under the conditions of 100 to 170°C and 1 to 30 minutes and the second heat treatment under the conditions of 140 to 200°C and 1 to 30 minutes with the proviso that the treatment temperature in the second heat treatment is set to be higher than that in the first heat treatment.