FILM-FORMING COMPOSITION COMPRISING INDIUM AND TIN COMPOUNDS

摘要

A film-forming composition comprises a mixture of (a) an organic solvent solution of an inorganic indium salt (e.g. chloride or nitrate) in amount of 0.5 to 30 wt% as InO, and an inorganic tin salt (e.g. chloride) in amount of 0.5 to 30 wt% of tin: indium, and (b) a nonaqueous 1 to 20 wt% silica sol, e.g. containing SiO2 particles of size 0.02 to 0.1 mu m added in amount of 1 to 200 wt% of SiO2:InO. Cellulosic compounds may be included as thickener. The composition is coated or printed on a flat substrate, e.g. glass plate, and air-dried at 40 to 250 DEG C and baked at 400 DEG to 900 DEG C to form a transparent film composed of an upper InSn oxide layer and lower SiO2 layer which is strongly adherent and absorbs no Na ions from soda glass and having good electrical conductivity (exemplified resistivities of 400 to 1500 ohms per square).