Abstract:
PROBLEM TO BE SOLVED: To provide a finishing agent which is for protecting a chemical conversion coating of a metal surface and is capable of imparting high corrosion resistance even to a thin film not containing chrome.SOLUTION: As the finishing agent for surface treatment for protecting the surface of a metal chemical conversion coating, a silicon compound and a rare earth element are used, and a corrosion resistance improving effect is increased by the interaction of the substances used in a treatment.
Abstract:
PROBLEM TO BE SOLVED: To solve such a problem that all of the erosion-resistance, appearance, and a friction coefficient can not be satisfied although the surface nature is improved by processing by a finishing agent containing oxyacid ion of phosphorous and trivalent chrome in a conventional chemical film formed on the surface of metals such as bolts and nuts haing friction faces.SOLUTION: The finished film satisfying all of the excellent erosion resistance, friction property, and appearance is formed by bringing a base body having the chemical film into contact with the finishing agent aqueous solution containing one kind or more of ions selected from the trivalent chrome and aluminum, and one kind or more of ions selected from oxyacid ion of phosphorous, and further Mg, Ca, Sr, and Ba.
Abstract:
PROBLEM TO BE SOLVED: To stably form a chromium-free chemical coating film having excellent corrosion resistance and uniform glossiness appearance regardless of a shape of a plating member and existence of heat treatment after plating.SOLUTION: A zinc plating member and a zinc alloy plating member is subjected to immersion treatment by using an acid reaction type chemical treatment liquid containing a vanadium group compound, a rare earth ion, a nitrate ion, occasionally one metal compound selected from Fe, Mg, Ca, Ni, Co, Zn, Y, La, Mo, W, Ti, Al, Zr, and Mn and a silicon compound according to circumstances and an inorganic, organic or organic inorganic composite coating film or a multilayer coating film is formed on a protective coating film after the treatment object is washed by water according to circumstances.