METHOD FOR MAKING SURFACE OF METAL WATER-REPELLENT

摘要

PURPOSE: To enhance the water repellency of the surface of a metal by coating the surface of the metal with a fluororesin and roughening the coated surface of the metal by blasting to bring the roughened surface of the metal into contact with fluorine gas. CONSTITUTION: A fluororesin is applied to the surface of a metal in a thickness of 20μm-10mm by a dip coating method and, subsequently, the coated surface of the metal is roughened by air blasting using a blast material such as glass >=200. Next, the blast material is washed in an aq. fluoric acid soln. with a concn. of about 15% using ultrasonic waves to be removed. This metal plate is put in a reactor and the reactor is reduced in pressure to about 0.2Torr and fluorine gas is introduced into the reactor up to about 50Torr. Reaction temp. is set to about 200 deg.C and the metal plate is brought into contact with the fluorine gas for about 30min to be treated.