To obtain a gold-contg. nanoporous aluminum oxide film capable of giving clear red decoration to the top of a baking-stable substrate by incorporating a ligand stabilized gold cluster into a nanoporous aluminum oxide film.
The gold-contg. nanoporous aluminum oxide film has open pares having 2-100 nm diameter in one face or both faces, contains a ligand stabilized gold cluster represented by the formula Au55L12X6/m and has 5-500 μm film thickness. The surface of aluminum is anodically oxidized in an aq. soln. contg. a dibasic acid such as sulfuric acid or oxalic acid, the resultant nanoporous aluminum oxide film is immersed in an aq. soln. of the ligand stabilized gold cluster to fill the soln. into the pores and deposits of the gold cluster are formed by evaporating the solvent to produce the gold-contg. nanoporous aluminum oxide film. This film is heated to 200-300°C and fixed on the top of a substrate of glass, whiteware or the like by baking at 500-1,000°C to obtain red decoration. In the formula, X is an m-valent anion and L is a ligand for stabilization contg. P, S and N, e.g. triphenylphosphine.
SCHMITZ GUENTER
HORNYAK GABOR LOUIS
SAWITOWSKI THOMAS
