A process for continuous manufacturing of steel strips for packaging coated with a passivation layer is provided. The layer is an aqueous passivation solution, the thickness of which is less than 3 m and the viscosity of which is less than 1.5.Math.10.sup.3 Pa.Math.s at 20 C., and is deposited on one of the faces of the strip. This depositing is carried out by a transfer roller in contact with the strip and with a second coating roller, the surface of which has a plurality of hexagonally shaped cells, the line count of which is between 50 and 200 lines per centimeter, and the total volume of which is between 5.Math.10.sup.6 and 10.Math.10.sup.6 m.sup.3 per square meter of roller surface. The coating roller is fed with aqueous passivation solution by dipping in a tank equipped with wiping means and the strip runs at a speed greater than or equal to 400 m/m. An apparatus for implementation of the process is also provided.

There is provided a technique to strongly integrate a galvanized steel sheet and a resin molded article. A hot-dip galvanized steel sheet is immersed in an aqueous solution for aluminum degreasing to form a specific roughness on the surface. The surface is covered with convex protrusions having a diameter of about 100 nm, and a chromate treatment layer appears in the surface. A resin composition comprising 70 to 97 wt % of polyphenylene sulfide and 3 to 30 wt % of a polyolefin resin is injected onto the surface. The resin composition penetrates into ultra-fine irregularities and is cured in that state, and thereby a composite in which the galvanized steel sheet and the resin molded article are strongly integrated can be obtained. The shear rupture strength of the composite is extremely high.

There is provided a technique to strongly integrate a galvanized steel sheet and a resin molded article. A hot-dip galvanized steel sheet is immersed in an aqueous solution for aluminum degreasing to form a specific roughness on the surface. The surface is covered with convex protrusions having a diameter of about 100 nm, and a chromate treatment layer appears in the surface. A resin composition comprising 70 to 97 wt % of polyphenylene sulfide and 3 to 30 wt % of a polyolefin resin is injected onto the surface. The resin composition penetrates into ultra-fine irregularities and is cured in that state, and thereby a composite in which the galvanized steel sheet and the resin molded article are strongly integrated can be obtained. The shear rupture strength of the composite is extremely high.

A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

Disclosed herein is a first composition comprising a trivalent chromium cation and an aqueous carrier. Also disclosed herein is a second composition comprising a permanganate anion and an aqueous carrier. Also disclosed herein is a system for treating a metal substrate comprising a first composition comprising a trivalent chromium cation and an aqueous carrier and optionally a second composition comprising a permanganate anion and an aqueous carrier. Also disclosed herein is a method of treating a metal substrate comprising contacting at least a portion of the substrate surface with a first composition comprising a trivalent chromium cation and an aqueous carrier and optionally contacting at least a portion of the substrate surface with a second composition comprising a permanganate anion and an aqueous carrier.

In one aspect, a spray foam chemical conversion coating includes a non-hexavalent chromium aqueous chemical conversion coating solution, a foaming agent, and a propellant. In another aspect, a method of producing a corrosion-resistant coating includes spraying a foam chemical conversion coating on a surface of a metal substrate, allowing the foam chemical conversion coating to react with the surface, and removing excess foam chemical conversion coating from the surface. The foam chemical conversion coating contains no hexavalent chromium.

A method of surface treatments that provide additional characteristics to the surfaces of galvanized steel materials is provided. A chromate-free coating material is applied after texturing on the surface of the galvanizing steel material and obtaining the roughness values. The resulting galvanized steel material provides a stainless-steel alternative sheet materials with high corrosion resistance and anti-fingerprint characteristics.

The present invention provides an aqueous surface treatment agent which is used for surface treatment of a metal and contains a trivalent chromium compound (A), a water-soluble or water-dispersible acrylic resin (B), a polyfunctional epoxy compound (C) and a phosphoric acid compound (D), wherein: the water-soluble or water-dispersible acrylic resin (B) has a weight average molecular weight of 30,000 to 1,000,000 and a solid acid value of 500 mgKOH/g to 780 mgKOH/g; the ratio of the mass of trivalent chromium contained in the trivalent chromium compound (A) to the total mass of solids is 3% to 15%; the ratio of the mass of solid content of the polyfunctional epoxy compound (C) to the total mass of solids is 1% to 15%; and the ratio of the mass of solid content of the phosphoric acid compound (D) to the total mass of solids is 5% to 25%.