RUST PREVENTIVE COMPOSITION

PROBLEM TO BE SOLVED: To obtain a rust preventive compsn. for blank metals which is capable of more effectively and safely removing the rust formed on the metals at ordinary temp. and is hard to cause the corrosion of blank metals by using a chelating agent and a semiconductor catalyst as essential components. SOLUTION: This result preventive compsn. is formed by using the chelating agent and the semiconductor catalyst as the essential components therein and incorporating a surfactant, etc., therein at need. Mineral acids, such as hydrochloric acid, which attack the blank metals are not used. The chelating agent described above is preferably oxalic acid, citric acid, EDTA and their salts. The semiconductor catalysts are preferably TiO2 , SnO2 , WO3 , SiO2 , Fe2 O3 and more particularly preferably TiO2 and Fe2 O3 . This compsn. is used by dissolving or dispersing in water or more preferably ion exchange water, and at this time, the chelating agent is preferably incorporated into the compsn. at about 0.1 to 50wt.% of the entire part thereof and the semiconductor photocatalyst at about 0.1 to 40%.