Abstract: The present invention addresses the problem of providing a chemical conversion treatment solution that contains zirconium ions and that makes it possible to form a highly corrosion-resistant chemical conversion coating formed with consideration for the environment as well. The present invention provides a chemical conversion treatment solution that contains trivalent chromium ions, zirconium ions, aluminum ions, at least one type of carboxylic acid ions, and at least one type of silicon compound, the chemical conversion treatment solution being free of fluorine ions and fluorine compounds.

Abstract: The purpose of the present invention is to provide a water-soluble finishing agent for a trivalent chromium chemical conversion coating film, which has low insulation, no problems with tightening properties, outstanding gloss and high corrosion resistance, and can obtain a trivalent chromium chemical conversion coating film, especially a black trivalent chromium chemical conversion coating film, having few scratches and flaws. The finishing agent for a trivalent chromium chemical conversion coating film is characterized by containing a trivalent chromium source, a phosphate ion source, a zinc ion source, a chelating agent which can form a complex with trivalent chromium, and a non-ionic water-soluble polymer compound selected from a group comprising poly(vinyl alcohol) and derivatives thereof, poly(vinyl pyrrolidone) and derivatives thereof, poly(alkylene glycol)s and derivatives thereof, and cellulose ethers and derivatives thereof.

Abstract: Provided is a method for regenerating a nitric acid active treatment solution comprising: adding a zinc ion-aggregating agent to a nitric acid active treatment solution for a surface of a zinc-based material plated metal member, the nitric acid active treatment solution containing zinc ions, to thereby aggregate the zinc ions in the solution as an insoluble salt; and separating and removing the insoluble salt.

Abstract: Provided is a method for regenerating a nitric acid active treatment solution comprising: adding a zinc ion-aggregating agent to a nitric acid active treatment solution for a surface of a zinc-based material plated metal member, the nitric acid active treatment solution containing zinc ions, to thereby aggregate the zinc ions in the solution as an insoluble salt; and separating and removing the insoluble salt.

Abstract: The purpose of the present invention is to provide a water-soluble finishing agent for a trivalent chromium chemical conversion coating film, which has low insulation, no problems with tightening properties, outstanding gloss and high corrosion resistance, and can obtain a trivalent chromium chemical conversion coating film, especially a black trivalent chromium chemical conversion coating film, having few scratches and flaws. The finishing agent for a trivalent chromium chemical conversion coating film is characterized by containing a trivalent chromium source, a phosphate ion source, a zinc ion source, a chelating agent which can form a complex with trivalent chromium, and a non-ionic water-soluble polymer compound selected from a group comprising poly(vinyl alcohol) and derivatives thereof, poly(vinyl pyrrolidone) and derivatives thereof, poly(alkylene glycol)s and derivatives thereof, and cellulose ethers and derivatives thereof.