摘要:
The invention relates to a process for treating metal surfaces, preferably of aluminum, aluminum alloys and steel, for the subsequent application of organic coating compositions. The metal surfaces are wetted with an aqueous bath solution containing chromium(III)ions, fluoride ions and an organic film former which is soluble or homogeneously dispersible in water, after which the solution applied is dried and converted by heating into a water-insoluble film.The bath solution preferably contains the following constituents and approximate quantities thereof: 0.5 to 10 g/l of chromium(III)ions, 0.55 to 11 g/l of fluoride ions, 0.6 to 12.5 g/l of phosphate ions, and 0.15 to 5.0 g/l of organic film former. The organic film former preferably used is a polymer containing free carboxyl groups, more preferably a homopolymer and/or copolymer of acrylic and/or methacrylic acid.
摘要:
A method for phosphate coating zinc or nickel-zinc alloy electrolytically coated metal surfaces, in which they are exposed to a phosphating solution containing zinc, manganese, and phosphate ions, and optionally cobalt and/or nitrate ions. The method is conducted at an elevated temperature for up to slightly more than 5 seconds.
摘要:
A process for phosphating a galvanized surface of a steel strip electrolytically galvanized on one side by contacting the galvanized surface of the steel strip with a phosphating solution containing 1.0 to 6 g/l zinc, 0.5 to 5.0 g/l nickel and 14 to 25 g/l phosphate at a temperature of 40.degree. to 70.degree. C. for from 2 to 20 seconds. The ungalvanized surface remains metal bright.
摘要:
A process for phosphating zinc-plated metal articles, particularly electrolytically zinc-plated steel sheets, by treatment thereof for a short period with an acidic phosphating solution which, in addition to zinc and phosphate ions, can contain other metal cations and/or anions of oxygen-containing acids having an accelerating effect, wherein the phosphating solution has a content of Zn.sup.2+ -cations of between about 1 and 2.5 g/l, a free acid content in the range from 0.8 to 3 points, and the acid ratio of total acid to free acid in the range from 5 to 10. The phosphating treatment is carried out for a period of time not in excess of about 5 seconds.
摘要:
Described is a process using a no-rinse technique for the production of a chromium-free conversion layer on the surface of aluminum and its alloys by treating with an aqueous solution having a pH between 1 and 3.5 and containing titanium and/or zirconium plus an organic film-forming agent. The process is characterized in that the surface is brought into contact with a solution containing a) 2.2 to 22.0 g/l of Zr(IV) and/or 1.4 to 14.0 g/l of Ti(IV), b) 2.4 to 24.0 g/l of orthophosphate, c) 3.0 to 30.0 g/l of fluoride, d) 0.15 to 1.5 g/l of a water-soluble or homogeneously water-dispersible organic film former and, after a contact time between 1 and 40 seconds, the wet surface is allowed to dry, without rinsing, at a temperature between 50.degree. and 125.degree. C. Also described are aqueous concentrates for use in the process.
摘要:
A process is disclosed for phosphating metallic surfaces, particularly electrolytically or hot dipped galvanized steel strip surfaces, by dip or spray processing the metallic surfaces with acidic aqueous phosphating solutions, wherein the workpieces are cathodically treated at the same time with a direct current. The process is characterized by (a) the use of phosphating solutions that contain the following components: Zn.sup.+2 cations in a range from 0.1 to 5 g/l; PO.sub.4.sup.-3 anions in a range from 5 to 50 g/l; NO.sub.3.sup.- anions in a range from 0.1 to 50 g/l; as well as Ni.sup.+2 cations in a range from 0.1 to 5 g/l and/or Co.sup.+2 cations in a range from 0.1 to 5 g/l; (b) the observance of the following conditions: pH value of the phosphating solutions in a range from 1.5 to 4.5; temperature of the phosphating solutions in a range from 10.degree. to 80.degree. C.; duration of treatment in a range from 1 to 300 sec, (c) simultaneous cathodic treatment of the workpiece during phosphating with a direct current having a density in the range from 0.01 to 100 mA/cm.sup.2.