PURPOSE: To keep a surface of a heavy metal to be water repellent and oil repellent under simple and mild treating condition at room temp. by applying a thione compound shown in specified plural formulas or a thiol compound of its tautomer, or a salt of the thiol compound.
CONSTITUTION: A surface of a heavy metal is kept to be water repellent and oil repellent by applying a specified thione compound or a thiol compound of its tautomer, or a salt of the thiol compound on the surface of the heavy metal. In this case, the thione compound is shown in attached formula (I) or (II). In formula (I), (n) is an integer of 6-9, L is a monovalent or divalent bonded group, Z is a residual group necessary to form a thiazoline ring, a triazoline ring, a tetraazoline ring, a dihydrotriazine ring or tetrahydrotriazine ring respectively. And in formula (II), (n) is an integer of 6-9, L is a divalent bonded group, R is hydrogen atom, lower alkyl group, lower alkenyl group or aryl group respectively.
IGUCHI SHIGERU
TAKADA MASAKAZU
